diff --git a/pkg/front_end/lib/src/fasta/builder/type_variable_builder.dart b/pkg/front_end/lib/src/fasta/builder/type_variable_builder.dart
index 93ee6da..db9c9ed 100644
--- a/pkg/front_end/lib/src/fasta/builder/type_variable_builder.dart
+++ b/pkg/front_end/lib/src/fasta/builder/type_variable_builder.dart
@@ -161,10 +161,13 @@
     // explicitly specified as Object, in which case defaultType should also be
     // Object. This makes sure instantiation of generic function types with an
     // explicit Object bound results in Object as the instantiated type.
-    parameter.defaultType ??= defaultType?.build(library) ??
-        (bound != null && parameter.bound == objectType
-            ? objectType
-            : dynamicType.build(library));
+    if (identical(
+        parameter.defaultType, TypeParameter.unsetDefaultTypeSentinel)) {
+      parameter.defaultType = defaultType?.build(library) ??
+          (bound != null && parameter.bound == objectType
+              ? objectType
+              : dynamicType.build(library));
+    }
   }
 
   void applyPatch(covariant TypeVariableBuilder patch) {
diff --git a/pkg/front_end/test/fasta/expression_suite.dart b/pkg/front_end/test/fasta/expression_suite.dart
index ddf7d48..4178a6f 100644
--- a/pkg/front_end/test/fasta/expression_suite.dart
+++ b/pkg/front_end/test/fasta/expression_suite.dart
@@ -313,7 +313,8 @@
     }
     List<TypeParameter> typeParams = [];
     for (String name in test.typeDefinitions) {
-      typeParams.add(new TypeParameter(name, new DynamicType()));
+      typeParams
+          .add(new TypeParameter(name, new DynamicType(), new DynamicType()));
     }
 
     Procedure compiledProcedure = await compiler.compileExpression(
diff --git a/pkg/front_end/test/fasta/types/kernel_type_parser_test.dart b/pkg/front_end/test/fasta/types/kernel_type_parser_test.dart
index 8d54c8a..6b31ffd 100644
--- a/pkg/front_end/test/fasta/types/kernel_type_parser_test.dart
+++ b/pkg/front_end/test/fasta/types/kernel_type_parser_test.dart
@@ -71,7 +71,7 @@
 }
 class bool extends self::Object {
 }
-class DefaultTypes<S extends self::Object? = dynamic, T extends self::Object = self::Object, U extends self::List<self::DefaultTypes::S%> = self::List<dynamic>, V extends self::List<self::DefaultTypes::T> = self::List<self::Object>, W extends self::Comparable<self::DefaultTypes::W> = self::Comparable<dynamic>, X extends (self::DefaultTypes::W) → void = (Never) → void, Y extends () → self::DefaultTypes::W = () → self::Comparable<dynamic>> extends self::Object {
+class DefaultTypes<S extends self::Object? = dynamic, T extends self::Object, U extends self::List<self::DefaultTypes::S%> = self::List<dynamic>, V extends self::List<self::DefaultTypes::T> = self::List<self::Object>, W extends self::Comparable<self::DefaultTypes::W> = self::Comparable<dynamic>, X extends (self::DefaultTypes::W) → void = (Never) → void, Y extends () → self::DefaultTypes::W = () → self::Comparable<dynamic>> extends self::Object {
 }
 class Super extends self::Object implements self::Comparable<self::Sub> {
 }
diff --git a/pkg/front_end/testcases/extensions/bounds.dart.weak.expect b/pkg/front_end/testcases/extensions/bounds.dart.weak.expect
index b7ca556..8c13b5c 100644
--- a/pkg/front_end/testcases/extensions/bounds.dart.weak.expect
+++ b/pkg/front_end/testcases/extensions/bounds.dart.weak.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-extension Extension1<T extends core::Object* = core::Object*> on T* {
+extension Extension1<T extends core::Object*> on T* {
   method method1 = self::Extension1|method1;
   tearoff method1 = self::Extension1|get#method1;
   method method2 = self::Extension1|method2;
@@ -12,7 +12,7 @@
   method method4 = self::Extension1|method4;
   tearoff method4 = self::Extension1|get#method4;
 }
-extension Extension2<T extends core::String* = core::String*> on T* {
+extension Extension2<T extends core::String*> on T* {
   method method1 = self::Extension2|method1;
   tearoff method1 = self::Extension2|get#method1;
   method method2 = self::Extension2|method2;
@@ -22,7 +22,7 @@
   method method4 = self::Extension2|method4;
   tearoff method4 = self::Extension2|get#method4;
 }
-extension Extension3<T extends dynamic = dynamic> on T* {
+extension Extension3<T extends dynamic> on T* {
   method method1 = self::Extension3|method1;
   tearoff method1 = self::Extension3|get#method1;
   method method2 = self::Extension3|method2;
@@ -42,51 +42,51 @@
   method method4 = self::Extension4|method4;
   tearoff method4 = self::Extension4|get#method4;
 }
-static method Extension1|method1<T extends core::Object* = core::Object*, S extends core::Object* = core::Object*>(lowered final self::Extension1|method1::T* #this) → dynamic {}
-static method Extension1|get#method1<T extends core::Object* = core::Object*>(lowered final self::Extension1|get#method1::T* #this) → <S extends core::Object* = core::Object*>() →* dynamic
-  return <S extends core::Object* = core::Object*>() → dynamic => self::Extension1|method1<self::Extension1|get#method1::T*, S*>(#this);
-static method Extension1|method2<T extends core::Object* = core::Object*, S extends core::String* = core::String*>(lowered final self::Extension1|method2::T* #this) → dynamic {}
-static method Extension1|get#method2<T extends core::Object* = core::Object*>(lowered final self::Extension1|get#method2::T* #this) → <S extends core::String* = core::String*>() →* dynamic
-  return <S extends core::String* = core::String*>() → dynamic => self::Extension1|method2<self::Extension1|get#method2::T*, S*>(#this);
-static method Extension1|method3<T extends core::Object* = core::Object*, S extends dynamic = dynamic>(lowered final self::Extension1|method3::T* #this) → dynamic {}
-static method Extension1|get#method3<T extends core::Object* = core::Object*>(lowered final self::Extension1|get#method3::T* #this) → <S extends dynamic = dynamic>() →* dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension1|method3<self::Extension1|get#method3::T*, S%>(#this);
-static method Extension1|method4<T extends core::Object* = core::Object*, S extends core::Object* = dynamic>(lowered final self::Extension1|method4::T* #this) → dynamic {}
-static method Extension1|get#method4<T extends core::Object* = core::Object*>(lowered final self::Extension1|get#method4::T* #this) → <S extends core::Object* = dynamic>() →* dynamic
+static method Extension1|method1<T extends core::Object*, S extends core::Object*>(lowered final self::Extension1|method1::T* #this) → dynamic {}
+static method Extension1|get#method1<T extends core::Object*>(lowered final self::Extension1|get#method1::T* #this) → <S extends core::Object*>() →* dynamic
+  return <S extends core::Object*>() → dynamic => self::Extension1|method1<self::Extension1|get#method1::T*, S*>(#this);
+static method Extension1|method2<T extends core::Object*, S extends core::String*>(lowered final self::Extension1|method2::T* #this) → dynamic {}
+static method Extension1|get#method2<T extends core::Object*>(lowered final self::Extension1|get#method2::T* #this) → <S extends core::String*>() →* dynamic
+  return <S extends core::String*>() → dynamic => self::Extension1|method2<self::Extension1|get#method2::T*, S*>(#this);
+static method Extension1|method3<T extends core::Object*, S extends dynamic>(lowered final self::Extension1|method3::T* #this) → dynamic {}
+static method Extension1|get#method3<T extends core::Object*>(lowered final self::Extension1|get#method3::T* #this) → <S extends dynamic>() →* dynamic
+  return <S extends dynamic>() → dynamic => self::Extension1|method3<self::Extension1|get#method3::T*, S%>(#this);
+static method Extension1|method4<T extends core::Object*, S extends core::Object* = dynamic>(lowered final self::Extension1|method4::T* #this) → dynamic {}
+static method Extension1|get#method4<T extends core::Object*>(lowered final self::Extension1|get#method4::T* #this) → <S extends core::Object* = dynamic>() →* dynamic
   return <S extends core::Object* = dynamic>() → dynamic => self::Extension1|method4<self::Extension1|get#method4::T*, S*>(#this);
-static method Extension2|method1<T extends core::String* = core::String*, S extends core::Object* = core::Object*>(lowered final self::Extension2|method1::T* #this) → dynamic {}
-static method Extension2|get#method1<T extends core::String* = core::String*>(lowered final self::Extension2|get#method1::T* #this) → <S extends core::Object* = core::Object*>() →* dynamic
-  return <S extends core::Object* = core::Object*>() → dynamic => self::Extension2|method1<self::Extension2|get#method1::T*, S*>(#this);
-static method Extension2|method2<T extends core::String* = core::String*, S extends core::String* = core::String*>(lowered final self::Extension2|method2::T* #this) → dynamic {}
-static method Extension2|get#method2<T extends core::String* = core::String*>(lowered final self::Extension2|get#method2::T* #this) → <S extends core::String* = core::String*>() →* dynamic
-  return <S extends core::String* = core::String*>() → dynamic => self::Extension2|method2<self::Extension2|get#method2::T*, S*>(#this);
-static method Extension2|method3<T extends core::String* = core::String*, S extends dynamic = dynamic>(lowered final self::Extension2|method3::T* #this) → dynamic {}
-static method Extension2|get#method3<T extends core::String* = core::String*>(lowered final self::Extension2|get#method3::T* #this) → <S extends dynamic = dynamic>() →* dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension2|method3<self::Extension2|get#method3::T*, S%>(#this);
-static method Extension2|method4<T extends core::String* = core::String*, S extends core::Object* = dynamic>(lowered final self::Extension2|method4::T* #this) → dynamic {}
-static method Extension2|get#method4<T extends core::String* = core::String*>(lowered final self::Extension2|get#method4::T* #this) → <S extends core::Object* = dynamic>() →* dynamic
+static method Extension2|method1<T extends core::String*, S extends core::Object*>(lowered final self::Extension2|method1::T* #this) → dynamic {}
+static method Extension2|get#method1<T extends core::String*>(lowered final self::Extension2|get#method1::T* #this) → <S extends core::Object*>() →* dynamic
+  return <S extends core::Object*>() → dynamic => self::Extension2|method1<self::Extension2|get#method1::T*, S*>(#this);
+static method Extension2|method2<T extends core::String*, S extends core::String*>(lowered final self::Extension2|method2::T* #this) → dynamic {}
+static method Extension2|get#method2<T extends core::String*>(lowered final self::Extension2|get#method2::T* #this) → <S extends core::String*>() →* dynamic
+  return <S extends core::String*>() → dynamic => self::Extension2|method2<self::Extension2|get#method2::T*, S*>(#this);
+static method Extension2|method3<T extends core::String*, S extends dynamic>(lowered final self::Extension2|method3::T* #this) → dynamic {}
+static method Extension2|get#method3<T extends core::String*>(lowered final self::Extension2|get#method3::T* #this) → <S extends dynamic>() →* dynamic
+  return <S extends dynamic>() → dynamic => self::Extension2|method3<self::Extension2|get#method3::T*, S%>(#this);
+static method Extension2|method4<T extends core::String*, S extends core::Object* = dynamic>(lowered final self::Extension2|method4::T* #this) → dynamic {}
+static method Extension2|get#method4<T extends core::String*>(lowered final self::Extension2|get#method4::T* #this) → <S extends core::Object* = dynamic>() →* dynamic
   return <S extends core::Object* = dynamic>() → dynamic => self::Extension2|method4<self::Extension2|get#method4::T*, S*>(#this);
-static method Extension3|method1<T extends dynamic = dynamic, S extends core::Object* = core::Object*>(lowered final self::Extension3|method1::T* #this) → dynamic {}
-static method Extension3|get#method1<T extends dynamic = dynamic>(lowered final self::Extension3|get#method1::T* #this) → <S extends core::Object* = core::Object*>() →* dynamic
-  return <S extends core::Object* = core::Object*>() → dynamic => self::Extension3|method1<self::Extension3|get#method1::T%, S*>(#this);
-static method Extension3|method2<T extends dynamic = dynamic, S extends core::String* = core::String*>(lowered final self::Extension3|method2::T* #this) → dynamic {}
-static method Extension3|get#method2<T extends dynamic = dynamic>(lowered final self::Extension3|get#method2::T* #this) → <S extends core::String* = core::String*>() →* dynamic
-  return <S extends core::String* = core::String*>() → dynamic => self::Extension3|method2<self::Extension3|get#method2::T%, S*>(#this);
-static method Extension3|method3<T extends dynamic = dynamic, S extends dynamic = dynamic>(lowered final self::Extension3|method3::T* #this) → dynamic {}
-static method Extension3|get#method3<T extends dynamic = dynamic>(lowered final self::Extension3|get#method3::T* #this) → <S extends dynamic = dynamic>() →* dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension3|method3<self::Extension3|get#method3::T%, S%>(#this);
-static method Extension3|method4<T extends dynamic = dynamic, S extends core::Object* = dynamic>(lowered final self::Extension3|method4::T* #this) → dynamic {}
-static method Extension3|get#method4<T extends dynamic = dynamic>(lowered final self::Extension3|get#method4::T* #this) → <S extends core::Object* = dynamic>() →* dynamic
+static method Extension3|method1<T extends dynamic, S extends core::Object*>(lowered final self::Extension3|method1::T* #this) → dynamic {}
+static method Extension3|get#method1<T extends dynamic>(lowered final self::Extension3|get#method1::T* #this) → <S extends core::Object*>() →* dynamic
+  return <S extends core::Object*>() → dynamic => self::Extension3|method1<self::Extension3|get#method1::T%, S*>(#this);
+static method Extension3|method2<T extends dynamic, S extends core::String*>(lowered final self::Extension3|method2::T* #this) → dynamic {}
+static method Extension3|get#method2<T extends dynamic>(lowered final self::Extension3|get#method2::T* #this) → <S extends core::String*>() →* dynamic
+  return <S extends core::String*>() → dynamic => self::Extension3|method2<self::Extension3|get#method2::T%, S*>(#this);
+static method Extension3|method3<T extends dynamic, S extends dynamic>(lowered final self::Extension3|method3::T* #this) → dynamic {}
+static method Extension3|get#method3<T extends dynamic>(lowered final self::Extension3|get#method3::T* #this) → <S extends dynamic>() →* dynamic
+  return <S extends dynamic>() → dynamic => self::Extension3|method3<self::Extension3|get#method3::T%, S%>(#this);
+static method Extension3|method4<T extends dynamic, S extends core::Object* = dynamic>(lowered final self::Extension3|method4::T* #this) → dynamic {}
+static method Extension3|get#method4<T extends dynamic>(lowered final self::Extension3|get#method4::T* #this) → <S extends core::Object* = dynamic>() →* dynamic
   return <S extends core::Object* = dynamic>() → dynamic => self::Extension3|method4<self::Extension3|get#method4::T%, S*>(#this);
-static method Extension4|method1<T extends core::Object* = dynamic, S extends core::Object* = core::Object*>(lowered final self::Extension4|method1::T* #this) → dynamic {}
-static method Extension4|get#method1<T extends core::Object* = dynamic>(lowered final self::Extension4|get#method1::T* #this) → <S extends core::Object* = core::Object*>() →* dynamic
-  return <S extends core::Object* = core::Object*>() → dynamic => self::Extension4|method1<self::Extension4|get#method1::T*, S*>(#this);
-static method Extension4|method2<T extends core::Object* = dynamic, S extends core::String* = core::String*>(lowered final self::Extension4|method2::T* #this) → dynamic {}
-static method Extension4|get#method2<T extends core::Object* = dynamic>(lowered final self::Extension4|get#method2::T* #this) → <S extends core::String* = core::String*>() →* dynamic
-  return <S extends core::String* = core::String*>() → dynamic => self::Extension4|method2<self::Extension4|get#method2::T*, S*>(#this);
-static method Extension4|method3<T extends core::Object* = dynamic, S extends dynamic = dynamic>(lowered final self::Extension4|method3::T* #this) → dynamic {}
-static method Extension4|get#method3<T extends core::Object* = dynamic>(lowered final self::Extension4|get#method3::T* #this) → <S extends dynamic = dynamic>() →* dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension4|method3<self::Extension4|get#method3::T*, S%>(#this);
+static method Extension4|method1<T extends core::Object* = dynamic, S extends core::Object*>(lowered final self::Extension4|method1::T* #this) → dynamic {}
+static method Extension4|get#method1<T extends core::Object* = dynamic>(lowered final self::Extension4|get#method1::T* #this) → <S extends core::Object*>() →* dynamic
+  return <S extends core::Object*>() → dynamic => self::Extension4|method1<self::Extension4|get#method1::T*, S*>(#this);
+static method Extension4|method2<T extends core::Object* = dynamic, S extends core::String*>(lowered final self::Extension4|method2::T* #this) → dynamic {}
+static method Extension4|get#method2<T extends core::Object* = dynamic>(lowered final self::Extension4|get#method2::T* #this) → <S extends core::String*>() →* dynamic
+  return <S extends core::String*>() → dynamic => self::Extension4|method2<self::Extension4|get#method2::T*, S*>(#this);
+static method Extension4|method3<T extends core::Object* = dynamic, S extends dynamic>(lowered final self::Extension4|method3::T* #this) → dynamic {}
+static method Extension4|get#method3<T extends core::Object* = dynamic>(lowered final self::Extension4|get#method3::T* #this) → <S extends dynamic>() →* dynamic
+  return <S extends dynamic>() → dynamic => self::Extension4|method3<self::Extension4|get#method3::T*, S%>(#this);
 static method Extension4|method4<T extends core::Object* = dynamic, S extends core::Object* = dynamic>(lowered final self::Extension4|method4::T* #this) → dynamic {}
 static method Extension4|get#method4<T extends core::Object* = dynamic>(lowered final self::Extension4|get#method4::T* #this) → <S extends core::Object* = dynamic>() →* dynamic
   return <S extends core::Object* = dynamic>() → dynamic => self::Extension4|method4<self::Extension4|get#method4::T*, S*>(#this);
diff --git a/pkg/front_end/testcases/extensions/bounds.dart.weak.outline.expect b/pkg/front_end/testcases/extensions/bounds.dart.weak.outline.expect
index 460599a..923a293 100644
--- a/pkg/front_end/testcases/extensions/bounds.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/extensions/bounds.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-extension Extension1<T extends core::Object* = core::Object*> on T* {
+extension Extension1<T extends core::Object*> on T* {
   method method1 = self::Extension1|method1;
   tearoff method1 = self::Extension1|get#method1;
   method method2 = self::Extension1|method2;
@@ -12,7 +12,7 @@
   method method4 = self::Extension1|method4;
   tearoff method4 = self::Extension1|get#method4;
 }
-extension Extension2<T extends core::String* = core::String*> on T* {
+extension Extension2<T extends core::String*> on T* {
   method method1 = self::Extension2|method1;
   tearoff method1 = self::Extension2|get#method1;
   method method2 = self::Extension2|method2;
@@ -22,7 +22,7 @@
   method method4 = self::Extension2|method4;
   tearoff method4 = self::Extension2|get#method4;
 }
-extension Extension3<T extends dynamic = dynamic> on T* {
+extension Extension3<T extends dynamic> on T* {
   method method1 = self::Extension3|method1;
   tearoff method1 = self::Extension3|get#method1;
   method method2 = self::Extension3|method2;
@@ -42,66 +42,66 @@
   method method4 = self::Extension4|method4;
   tearoff method4 = self::Extension4|get#method4;
 }
-static method Extension1|method1<T extends core::Object* = core::Object*, S extends core::Object* = core::Object*>(lowered final self::Extension1|method1::T* #this) → dynamic
+static method Extension1|method1<T extends core::Object*, S extends core::Object*>(lowered final self::Extension1|method1::T* #this) → dynamic
   ;
-static method Extension1|get#method1<T extends core::Object* = core::Object*>(lowered final self::Extension1|get#method1::T* #this) → <S extends core::Object* = core::Object*>() →* dynamic
-  return <S extends core::Object* = core::Object*>() → dynamic => self::Extension1|method1<self::Extension1|get#method1::T*, S*>(#this);
-static method Extension1|method2<T extends core::Object* = core::Object*, S extends core::String* = core::String*>(lowered final self::Extension1|method2::T* #this) → dynamic
+static method Extension1|get#method1<T extends core::Object*>(lowered final self::Extension1|get#method1::T* #this) → <S extends core::Object*>() →* dynamic
+  return <S extends core::Object*>() → dynamic => self::Extension1|method1<self::Extension1|get#method1::T*, S*>(#this);
+static method Extension1|method2<T extends core::Object*, S extends core::String*>(lowered final self::Extension1|method2::T* #this) → dynamic
   ;
-static method Extension1|get#method2<T extends core::Object* = core::Object*>(lowered final self::Extension1|get#method2::T* #this) → <S extends core::String* = core::String*>() →* dynamic
-  return <S extends core::String* = core::String*>() → dynamic => self::Extension1|method2<self::Extension1|get#method2::T*, S*>(#this);
-static method Extension1|method3<T extends core::Object* = core::Object*, S extends dynamic = dynamic>(lowered final self::Extension1|method3::T* #this) → dynamic
+static method Extension1|get#method2<T extends core::Object*>(lowered final self::Extension1|get#method2::T* #this) → <S extends core::String*>() →* dynamic
+  return <S extends core::String*>() → dynamic => self::Extension1|method2<self::Extension1|get#method2::T*, S*>(#this);
+static method Extension1|method3<T extends core::Object*, S extends dynamic>(lowered final self::Extension1|method3::T* #this) → dynamic
   ;
-static method Extension1|get#method3<T extends core::Object* = core::Object*>(lowered final self::Extension1|get#method3::T* #this) → <S extends dynamic = dynamic>() →* dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension1|method3<self::Extension1|get#method3::T*, S%>(#this);
-static method Extension1|method4<T extends core::Object* = core::Object*, S extends core::Object* = dynamic>(lowered final self::Extension1|method4::T* #this) → dynamic
+static method Extension1|get#method3<T extends core::Object*>(lowered final self::Extension1|get#method3::T* #this) → <S extends dynamic>() →* dynamic
+  return <S extends dynamic>() → dynamic => self::Extension1|method3<self::Extension1|get#method3::T*, S%>(#this);
+static method Extension1|method4<T extends core::Object*, S extends core::Object* = dynamic>(lowered final self::Extension1|method4::T* #this) → dynamic
   ;
-static method Extension1|get#method4<T extends core::Object* = core::Object*>(lowered final self::Extension1|get#method4::T* #this) → <S extends core::Object* = dynamic>() →* dynamic
+static method Extension1|get#method4<T extends core::Object*>(lowered final self::Extension1|get#method4::T* #this) → <S extends core::Object* = dynamic>() →* dynamic
   return <S extends core::Object* = dynamic>() → dynamic => self::Extension1|method4<self::Extension1|get#method4::T*, S*>(#this);
-static method Extension2|method1<T extends core::String* = core::String*, S extends core::Object* = core::Object*>(lowered final self::Extension2|method1::T* #this) → dynamic
+static method Extension2|method1<T extends core::String*, S extends core::Object*>(lowered final self::Extension2|method1::T* #this) → dynamic
   ;
-static method Extension2|get#method1<T extends core::String* = core::String*>(lowered final self::Extension2|get#method1::T* #this) → <S extends core::Object* = core::Object*>() →* dynamic
-  return <S extends core::Object* = core::Object*>() → dynamic => self::Extension2|method1<self::Extension2|get#method1::T*, S*>(#this);
-static method Extension2|method2<T extends core::String* = core::String*, S extends core::String* = core::String*>(lowered final self::Extension2|method2::T* #this) → dynamic
+static method Extension2|get#method1<T extends core::String*>(lowered final self::Extension2|get#method1::T* #this) → <S extends core::Object*>() →* dynamic
+  return <S extends core::Object*>() → dynamic => self::Extension2|method1<self::Extension2|get#method1::T*, S*>(#this);
+static method Extension2|method2<T extends core::String*, S extends core::String*>(lowered final self::Extension2|method2::T* #this) → dynamic
   ;
-static method Extension2|get#method2<T extends core::String* = core::String*>(lowered final self::Extension2|get#method2::T* #this) → <S extends core::String* = core::String*>() →* dynamic
-  return <S extends core::String* = core::String*>() → dynamic => self::Extension2|method2<self::Extension2|get#method2::T*, S*>(#this);
-static method Extension2|method3<T extends core::String* = core::String*, S extends dynamic = dynamic>(lowered final self::Extension2|method3::T* #this) → dynamic
+static method Extension2|get#method2<T extends core::String*>(lowered final self::Extension2|get#method2::T* #this) → <S extends core::String*>() →* dynamic
+  return <S extends core::String*>() → dynamic => self::Extension2|method2<self::Extension2|get#method2::T*, S*>(#this);
+static method Extension2|method3<T extends core::String*, S extends dynamic>(lowered final self::Extension2|method3::T* #this) → dynamic
   ;
-static method Extension2|get#method3<T extends core::String* = core::String*>(lowered final self::Extension2|get#method3::T* #this) → <S extends dynamic = dynamic>() →* dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension2|method3<self::Extension2|get#method3::T*, S%>(#this);
-static method Extension2|method4<T extends core::String* = core::String*, S extends core::Object* = dynamic>(lowered final self::Extension2|method4::T* #this) → dynamic
+static method Extension2|get#method3<T extends core::String*>(lowered final self::Extension2|get#method3::T* #this) → <S extends dynamic>() →* dynamic
+  return <S extends dynamic>() → dynamic => self::Extension2|method3<self::Extension2|get#method3::T*, S%>(#this);
+static method Extension2|method4<T extends core::String*, S extends core::Object* = dynamic>(lowered final self::Extension2|method4::T* #this) → dynamic
   ;
-static method Extension2|get#method4<T extends core::String* = core::String*>(lowered final self::Extension2|get#method4::T* #this) → <S extends core::Object* = dynamic>() →* dynamic
+static method Extension2|get#method4<T extends core::String*>(lowered final self::Extension2|get#method4::T* #this) → <S extends core::Object* = dynamic>() →* dynamic
   return <S extends core::Object* = dynamic>() → dynamic => self::Extension2|method4<self::Extension2|get#method4::T*, S*>(#this);
-static method Extension3|method1<T extends dynamic = dynamic, S extends core::Object* = core::Object*>(lowered final self::Extension3|method1::T* #this) → dynamic
+static method Extension3|method1<T extends dynamic, S extends core::Object*>(lowered final self::Extension3|method1::T* #this) → dynamic
   ;
-static method Extension3|get#method1<T extends dynamic = dynamic>(lowered final self::Extension3|get#method1::T* #this) → <S extends core::Object* = core::Object*>() →* dynamic
-  return <S extends core::Object* = core::Object*>() → dynamic => self::Extension3|method1<self::Extension3|get#method1::T%, S*>(#this);
-static method Extension3|method2<T extends dynamic = dynamic, S extends core::String* = core::String*>(lowered final self::Extension3|method2::T* #this) → dynamic
+static method Extension3|get#method1<T extends dynamic>(lowered final self::Extension3|get#method1::T* #this) → <S extends core::Object*>() →* dynamic
+  return <S extends core::Object*>() → dynamic => self::Extension3|method1<self::Extension3|get#method1::T%, S*>(#this);
+static method Extension3|method2<T extends dynamic, S extends core::String*>(lowered final self::Extension3|method2::T* #this) → dynamic
   ;
-static method Extension3|get#method2<T extends dynamic = dynamic>(lowered final self::Extension3|get#method2::T* #this) → <S extends core::String* = core::String*>() →* dynamic
-  return <S extends core::String* = core::String*>() → dynamic => self::Extension3|method2<self::Extension3|get#method2::T%, S*>(#this);
-static method Extension3|method3<T extends dynamic = dynamic, S extends dynamic = dynamic>(lowered final self::Extension3|method3::T* #this) → dynamic
+static method Extension3|get#method2<T extends dynamic>(lowered final self::Extension3|get#method2::T* #this) → <S extends core::String*>() →* dynamic
+  return <S extends core::String*>() → dynamic => self::Extension3|method2<self::Extension3|get#method2::T%, S*>(#this);
+static method Extension3|method3<T extends dynamic, S extends dynamic>(lowered final self::Extension3|method3::T* #this) → dynamic
   ;
-static method Extension3|get#method3<T extends dynamic = dynamic>(lowered final self::Extension3|get#method3::T* #this) → <S extends dynamic = dynamic>() →* dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension3|method3<self::Extension3|get#method3::T%, S%>(#this);
-static method Extension3|method4<T extends dynamic = dynamic, S extends core::Object* = dynamic>(lowered final self::Extension3|method4::T* #this) → dynamic
+static method Extension3|get#method3<T extends dynamic>(lowered final self::Extension3|get#method3::T* #this) → <S extends dynamic>() →* dynamic
+  return <S extends dynamic>() → dynamic => self::Extension3|method3<self::Extension3|get#method3::T%, S%>(#this);
+static method Extension3|method4<T extends dynamic, S extends core::Object* = dynamic>(lowered final self::Extension3|method4::T* #this) → dynamic
   ;
-static method Extension3|get#method4<T extends dynamic = dynamic>(lowered final self::Extension3|get#method4::T* #this) → <S extends core::Object* = dynamic>() →* dynamic
+static method Extension3|get#method4<T extends dynamic>(lowered final self::Extension3|get#method4::T* #this) → <S extends core::Object* = dynamic>() →* dynamic
   return <S extends core::Object* = dynamic>() → dynamic => self::Extension3|method4<self::Extension3|get#method4::T%, S*>(#this);
-static method Extension4|method1<T extends core::Object* = dynamic, S extends core::Object* = core::Object*>(lowered final self::Extension4|method1::T* #this) → dynamic
+static method Extension4|method1<T extends core::Object* = dynamic, S extends core::Object*>(lowered final self::Extension4|method1::T* #this) → dynamic
   ;
-static method Extension4|get#method1<T extends core::Object* = dynamic>(lowered final self::Extension4|get#method1::T* #this) → <S extends core::Object* = core::Object*>() →* dynamic
-  return <S extends core::Object* = core::Object*>() → dynamic => self::Extension4|method1<self::Extension4|get#method1::T*, S*>(#this);
-static method Extension4|method2<T extends core::Object* = dynamic, S extends core::String* = core::String*>(lowered final self::Extension4|method2::T* #this) → dynamic
+static method Extension4|get#method1<T extends core::Object* = dynamic>(lowered final self::Extension4|get#method1::T* #this) → <S extends core::Object*>() →* dynamic
+  return <S extends core::Object*>() → dynamic => self::Extension4|method1<self::Extension4|get#method1::T*, S*>(#this);
+static method Extension4|method2<T extends core::Object* = dynamic, S extends core::String*>(lowered final self::Extension4|method2::T* #this) → dynamic
   ;
-static method Extension4|get#method2<T extends core::Object* = dynamic>(lowered final self::Extension4|get#method2::T* #this) → <S extends core::String* = core::String*>() →* dynamic
-  return <S extends core::String* = core::String*>() → dynamic => self::Extension4|method2<self::Extension4|get#method2::T*, S*>(#this);
-static method Extension4|method3<T extends core::Object* = dynamic, S extends dynamic = dynamic>(lowered final self::Extension4|method3::T* #this) → dynamic
+static method Extension4|get#method2<T extends core::Object* = dynamic>(lowered final self::Extension4|get#method2::T* #this) → <S extends core::String*>() →* dynamic
+  return <S extends core::String*>() → dynamic => self::Extension4|method2<self::Extension4|get#method2::T*, S*>(#this);
+static method Extension4|method3<T extends core::Object* = dynamic, S extends dynamic>(lowered final self::Extension4|method3::T* #this) → dynamic
   ;
-static method Extension4|get#method3<T extends core::Object* = dynamic>(lowered final self::Extension4|get#method3::T* #this) → <S extends dynamic = dynamic>() →* dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension4|method3<self::Extension4|get#method3::T*, S%>(#this);
+static method Extension4|get#method3<T extends core::Object* = dynamic>(lowered final self::Extension4|get#method3::T* #this) → <S extends dynamic>() →* dynamic
+  return <S extends dynamic>() → dynamic => self::Extension4|method3<self::Extension4|get#method3::T*, S%>(#this);
 static method Extension4|method4<T extends core::Object* = dynamic, S extends core::Object* = dynamic>(lowered final self::Extension4|method4::T* #this) → dynamic
   ;
 static method Extension4|get#method4<T extends core::Object* = dynamic>(lowered final self::Extension4|get#method4::T* #this) → <S extends core::Object* = dynamic>() →* dynamic
diff --git a/pkg/front_end/testcases/extensions/bounds.dart.weak.transformed.expect b/pkg/front_end/testcases/extensions/bounds.dart.weak.transformed.expect
index b7ca556..8c13b5c 100644
--- a/pkg/front_end/testcases/extensions/bounds.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/extensions/bounds.dart.weak.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-extension Extension1<T extends core::Object* = core::Object*> on T* {
+extension Extension1<T extends core::Object*> on T* {
   method method1 = self::Extension1|method1;
   tearoff method1 = self::Extension1|get#method1;
   method method2 = self::Extension1|method2;
@@ -12,7 +12,7 @@
   method method4 = self::Extension1|method4;
   tearoff method4 = self::Extension1|get#method4;
 }
-extension Extension2<T extends core::String* = core::String*> on T* {
+extension Extension2<T extends core::String*> on T* {
   method method1 = self::Extension2|method1;
   tearoff method1 = self::Extension2|get#method1;
   method method2 = self::Extension2|method2;
@@ -22,7 +22,7 @@
   method method4 = self::Extension2|method4;
   tearoff method4 = self::Extension2|get#method4;
 }
-extension Extension3<T extends dynamic = dynamic> on T* {
+extension Extension3<T extends dynamic> on T* {
   method method1 = self::Extension3|method1;
   tearoff method1 = self::Extension3|get#method1;
   method method2 = self::Extension3|method2;
@@ -42,51 +42,51 @@
   method method4 = self::Extension4|method4;
   tearoff method4 = self::Extension4|get#method4;
 }
-static method Extension1|method1<T extends core::Object* = core::Object*, S extends core::Object* = core::Object*>(lowered final self::Extension1|method1::T* #this) → dynamic {}
-static method Extension1|get#method1<T extends core::Object* = core::Object*>(lowered final self::Extension1|get#method1::T* #this) → <S extends core::Object* = core::Object*>() →* dynamic
-  return <S extends core::Object* = core::Object*>() → dynamic => self::Extension1|method1<self::Extension1|get#method1::T*, S*>(#this);
-static method Extension1|method2<T extends core::Object* = core::Object*, S extends core::String* = core::String*>(lowered final self::Extension1|method2::T* #this) → dynamic {}
-static method Extension1|get#method2<T extends core::Object* = core::Object*>(lowered final self::Extension1|get#method2::T* #this) → <S extends core::String* = core::String*>() →* dynamic
-  return <S extends core::String* = core::String*>() → dynamic => self::Extension1|method2<self::Extension1|get#method2::T*, S*>(#this);
-static method Extension1|method3<T extends core::Object* = core::Object*, S extends dynamic = dynamic>(lowered final self::Extension1|method3::T* #this) → dynamic {}
-static method Extension1|get#method3<T extends core::Object* = core::Object*>(lowered final self::Extension1|get#method3::T* #this) → <S extends dynamic = dynamic>() →* dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension1|method3<self::Extension1|get#method3::T*, S%>(#this);
-static method Extension1|method4<T extends core::Object* = core::Object*, S extends core::Object* = dynamic>(lowered final self::Extension1|method4::T* #this) → dynamic {}
-static method Extension1|get#method4<T extends core::Object* = core::Object*>(lowered final self::Extension1|get#method4::T* #this) → <S extends core::Object* = dynamic>() →* dynamic
+static method Extension1|method1<T extends core::Object*, S extends core::Object*>(lowered final self::Extension1|method1::T* #this) → dynamic {}
+static method Extension1|get#method1<T extends core::Object*>(lowered final self::Extension1|get#method1::T* #this) → <S extends core::Object*>() →* dynamic
+  return <S extends core::Object*>() → dynamic => self::Extension1|method1<self::Extension1|get#method1::T*, S*>(#this);
+static method Extension1|method2<T extends core::Object*, S extends core::String*>(lowered final self::Extension1|method2::T* #this) → dynamic {}
+static method Extension1|get#method2<T extends core::Object*>(lowered final self::Extension1|get#method2::T* #this) → <S extends core::String*>() →* dynamic
+  return <S extends core::String*>() → dynamic => self::Extension1|method2<self::Extension1|get#method2::T*, S*>(#this);
+static method Extension1|method3<T extends core::Object*, S extends dynamic>(lowered final self::Extension1|method3::T* #this) → dynamic {}
+static method Extension1|get#method3<T extends core::Object*>(lowered final self::Extension1|get#method3::T* #this) → <S extends dynamic>() →* dynamic
+  return <S extends dynamic>() → dynamic => self::Extension1|method3<self::Extension1|get#method3::T*, S%>(#this);
+static method Extension1|method4<T extends core::Object*, S extends core::Object* = dynamic>(lowered final self::Extension1|method4::T* #this) → dynamic {}
+static method Extension1|get#method4<T extends core::Object*>(lowered final self::Extension1|get#method4::T* #this) → <S extends core::Object* = dynamic>() →* dynamic
   return <S extends core::Object* = dynamic>() → dynamic => self::Extension1|method4<self::Extension1|get#method4::T*, S*>(#this);
-static method Extension2|method1<T extends core::String* = core::String*, S extends core::Object* = core::Object*>(lowered final self::Extension2|method1::T* #this) → dynamic {}
-static method Extension2|get#method1<T extends core::String* = core::String*>(lowered final self::Extension2|get#method1::T* #this) → <S extends core::Object* = core::Object*>() →* dynamic
-  return <S extends core::Object* = core::Object*>() → dynamic => self::Extension2|method1<self::Extension2|get#method1::T*, S*>(#this);
-static method Extension2|method2<T extends core::String* = core::String*, S extends core::String* = core::String*>(lowered final self::Extension2|method2::T* #this) → dynamic {}
-static method Extension2|get#method2<T extends core::String* = core::String*>(lowered final self::Extension2|get#method2::T* #this) → <S extends core::String* = core::String*>() →* dynamic
-  return <S extends core::String* = core::String*>() → dynamic => self::Extension2|method2<self::Extension2|get#method2::T*, S*>(#this);
-static method Extension2|method3<T extends core::String* = core::String*, S extends dynamic = dynamic>(lowered final self::Extension2|method3::T* #this) → dynamic {}
-static method Extension2|get#method3<T extends core::String* = core::String*>(lowered final self::Extension2|get#method3::T* #this) → <S extends dynamic = dynamic>() →* dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension2|method3<self::Extension2|get#method3::T*, S%>(#this);
-static method Extension2|method4<T extends core::String* = core::String*, S extends core::Object* = dynamic>(lowered final self::Extension2|method4::T* #this) → dynamic {}
-static method Extension2|get#method4<T extends core::String* = core::String*>(lowered final self::Extension2|get#method4::T* #this) → <S extends core::Object* = dynamic>() →* dynamic
+static method Extension2|method1<T extends core::String*, S extends core::Object*>(lowered final self::Extension2|method1::T* #this) → dynamic {}
+static method Extension2|get#method1<T extends core::String*>(lowered final self::Extension2|get#method1::T* #this) → <S extends core::Object*>() →* dynamic
+  return <S extends core::Object*>() → dynamic => self::Extension2|method1<self::Extension2|get#method1::T*, S*>(#this);
+static method Extension2|method2<T extends core::String*, S extends core::String*>(lowered final self::Extension2|method2::T* #this) → dynamic {}
+static method Extension2|get#method2<T extends core::String*>(lowered final self::Extension2|get#method2::T* #this) → <S extends core::String*>() →* dynamic
+  return <S extends core::String*>() → dynamic => self::Extension2|method2<self::Extension2|get#method2::T*, S*>(#this);
+static method Extension2|method3<T extends core::String*, S extends dynamic>(lowered final self::Extension2|method3::T* #this) → dynamic {}
+static method Extension2|get#method3<T extends core::String*>(lowered final self::Extension2|get#method3::T* #this) → <S extends dynamic>() →* dynamic
+  return <S extends dynamic>() → dynamic => self::Extension2|method3<self::Extension2|get#method3::T*, S%>(#this);
+static method Extension2|method4<T extends core::String*, S extends core::Object* = dynamic>(lowered final self::Extension2|method4::T* #this) → dynamic {}
+static method Extension2|get#method4<T extends core::String*>(lowered final self::Extension2|get#method4::T* #this) → <S extends core::Object* = dynamic>() →* dynamic
   return <S extends core::Object* = dynamic>() → dynamic => self::Extension2|method4<self::Extension2|get#method4::T*, S*>(#this);
-static method Extension3|method1<T extends dynamic = dynamic, S extends core::Object* = core::Object*>(lowered final self::Extension3|method1::T* #this) → dynamic {}
-static method Extension3|get#method1<T extends dynamic = dynamic>(lowered final self::Extension3|get#method1::T* #this) → <S extends core::Object* = core::Object*>() →* dynamic
-  return <S extends core::Object* = core::Object*>() → dynamic => self::Extension3|method1<self::Extension3|get#method1::T%, S*>(#this);
-static method Extension3|method2<T extends dynamic = dynamic, S extends core::String* = core::String*>(lowered final self::Extension3|method2::T* #this) → dynamic {}
-static method Extension3|get#method2<T extends dynamic = dynamic>(lowered final self::Extension3|get#method2::T* #this) → <S extends core::String* = core::String*>() →* dynamic
-  return <S extends core::String* = core::String*>() → dynamic => self::Extension3|method2<self::Extension3|get#method2::T%, S*>(#this);
-static method Extension3|method3<T extends dynamic = dynamic, S extends dynamic = dynamic>(lowered final self::Extension3|method3::T* #this) → dynamic {}
-static method Extension3|get#method3<T extends dynamic = dynamic>(lowered final self::Extension3|get#method3::T* #this) → <S extends dynamic = dynamic>() →* dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension3|method3<self::Extension3|get#method3::T%, S%>(#this);
-static method Extension3|method4<T extends dynamic = dynamic, S extends core::Object* = dynamic>(lowered final self::Extension3|method4::T* #this) → dynamic {}
-static method Extension3|get#method4<T extends dynamic = dynamic>(lowered final self::Extension3|get#method4::T* #this) → <S extends core::Object* = dynamic>() →* dynamic
+static method Extension3|method1<T extends dynamic, S extends core::Object*>(lowered final self::Extension3|method1::T* #this) → dynamic {}
+static method Extension3|get#method1<T extends dynamic>(lowered final self::Extension3|get#method1::T* #this) → <S extends core::Object*>() →* dynamic
+  return <S extends core::Object*>() → dynamic => self::Extension3|method1<self::Extension3|get#method1::T%, S*>(#this);
+static method Extension3|method2<T extends dynamic, S extends core::String*>(lowered final self::Extension3|method2::T* #this) → dynamic {}
+static method Extension3|get#method2<T extends dynamic>(lowered final self::Extension3|get#method2::T* #this) → <S extends core::String*>() →* dynamic
+  return <S extends core::String*>() → dynamic => self::Extension3|method2<self::Extension3|get#method2::T%, S*>(#this);
+static method Extension3|method3<T extends dynamic, S extends dynamic>(lowered final self::Extension3|method3::T* #this) → dynamic {}
+static method Extension3|get#method3<T extends dynamic>(lowered final self::Extension3|get#method3::T* #this) → <S extends dynamic>() →* dynamic
+  return <S extends dynamic>() → dynamic => self::Extension3|method3<self::Extension3|get#method3::T%, S%>(#this);
+static method Extension3|method4<T extends dynamic, S extends core::Object* = dynamic>(lowered final self::Extension3|method4::T* #this) → dynamic {}
+static method Extension3|get#method4<T extends dynamic>(lowered final self::Extension3|get#method4::T* #this) → <S extends core::Object* = dynamic>() →* dynamic
   return <S extends core::Object* = dynamic>() → dynamic => self::Extension3|method4<self::Extension3|get#method4::T%, S*>(#this);
-static method Extension4|method1<T extends core::Object* = dynamic, S extends core::Object* = core::Object*>(lowered final self::Extension4|method1::T* #this) → dynamic {}
-static method Extension4|get#method1<T extends core::Object* = dynamic>(lowered final self::Extension4|get#method1::T* #this) → <S extends core::Object* = core::Object*>() →* dynamic
-  return <S extends core::Object* = core::Object*>() → dynamic => self::Extension4|method1<self::Extension4|get#method1::T*, S*>(#this);
-static method Extension4|method2<T extends core::Object* = dynamic, S extends core::String* = core::String*>(lowered final self::Extension4|method2::T* #this) → dynamic {}
-static method Extension4|get#method2<T extends core::Object* = dynamic>(lowered final self::Extension4|get#method2::T* #this) → <S extends core::String* = core::String*>() →* dynamic
-  return <S extends core::String* = core::String*>() → dynamic => self::Extension4|method2<self::Extension4|get#method2::T*, S*>(#this);
-static method Extension4|method3<T extends core::Object* = dynamic, S extends dynamic = dynamic>(lowered final self::Extension4|method3::T* #this) → dynamic {}
-static method Extension4|get#method3<T extends core::Object* = dynamic>(lowered final self::Extension4|get#method3::T* #this) → <S extends dynamic = dynamic>() →* dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension4|method3<self::Extension4|get#method3::T*, S%>(#this);
+static method Extension4|method1<T extends core::Object* = dynamic, S extends core::Object*>(lowered final self::Extension4|method1::T* #this) → dynamic {}
+static method Extension4|get#method1<T extends core::Object* = dynamic>(lowered final self::Extension4|get#method1::T* #this) → <S extends core::Object*>() →* dynamic
+  return <S extends core::Object*>() → dynamic => self::Extension4|method1<self::Extension4|get#method1::T*, S*>(#this);
+static method Extension4|method2<T extends core::Object* = dynamic, S extends core::String*>(lowered final self::Extension4|method2::T* #this) → dynamic {}
+static method Extension4|get#method2<T extends core::Object* = dynamic>(lowered final self::Extension4|get#method2::T* #this) → <S extends core::String*>() →* dynamic
+  return <S extends core::String*>() → dynamic => self::Extension4|method2<self::Extension4|get#method2::T*, S*>(#this);
+static method Extension4|method3<T extends core::Object* = dynamic, S extends dynamic>(lowered final self::Extension4|method3::T* #this) → dynamic {}
+static method Extension4|get#method3<T extends core::Object* = dynamic>(lowered final self::Extension4|get#method3::T* #this) → <S extends dynamic>() →* dynamic
+  return <S extends dynamic>() → dynamic => self::Extension4|method3<self::Extension4|get#method3::T*, S%>(#this);
 static method Extension4|method4<T extends core::Object* = dynamic, S extends core::Object* = dynamic>(lowered final self::Extension4|method4::T* #this) → dynamic {}
 static method Extension4|get#method4<T extends core::Object* = dynamic>(lowered final self::Extension4|get#method4::T* #this) → <S extends core::Object* = dynamic>() →* dynamic
   return <S extends core::Object* = dynamic>() → dynamic => self::Extension4|method4<self::Extension4|get#method4::T*, S*>(#this);
diff --git a/pkg/front_end/testcases/extensions/check_bounds.dart.weak.expect b/pkg/front_end/testcases/extensions/check_bounds.dart.weak.expect
index 635468b..cef7b3b 100644
--- a/pkg/front_end/testcases/extensions/check_bounds.dart.weak.expect
+++ b/pkg/front_end/testcases/extensions/check_bounds.dart.weak.expect
@@ -827,7 +827,7 @@
     : super self::A::•()
     ;
 }
-class Class<T extends self::A* = self::A*> extends core::Object {
+class Class<T extends self::A*> extends core::Object {
   synthetic constructor •() → self::Class<self::Class::T*>*
     : super core::Object::•()
     ;
@@ -842,7 +842,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-extension Extension<T extends self::B* = self::B*> on self::Class<T*>* {
+extension Extension<T extends self::B*> on self::Class<T*>* {
   method method = self::Extension|method;
   tearoff method = self::Extension|get#method;
   method genericMethod = self::Extension|genericMethod;
@@ -885,12 +885,12 @@
 static final field dynamic field27 = self::Extension|genericMethod<self::B*, self::A*>(self::classB, self::a);
 static final field dynamic field28 = self::Extension|genericMethod<self::B*, self::A*>(self::classB, self::a);
 static final field dynamic field29 = self::Extension|genericMethod<self::B*, self::B*>(self::classB, self::a as{TypeError} self::B*);
-static method Extension|method<T extends self::B* = self::B*>(lowered final self::Class<self::Extension|method::T*>* #this) → dynamic {}
-static method Extension|get#method<T extends self::B* = self::B*>(lowered final self::Class<self::Extension|get#method::T*>* #this) → () →* dynamic
+static method Extension|method<T extends self::B*>(lowered final self::Class<self::Extension|method::T*>* #this) → dynamic {}
+static method Extension|get#method<T extends self::B*>(lowered final self::Class<self::Extension|get#method::T*>* #this) → () →* dynamic
   return () → dynamic => self::Extension|method<self::Extension|get#method::T*>(#this);
-static method Extension|genericMethod<T extends self::B* = self::B*, S extends self::B* = self::B*>(lowered final self::Class<self::Extension|genericMethod::T*>* #this, self::Extension|genericMethod::S* s) → dynamic {}
-static method Extension|get#genericMethod<T extends self::B* = self::B*>(lowered final self::Class<self::Extension|get#genericMethod::T*>* #this) → <S extends self::B* = self::B*>(S*) →* dynamic
-  return <S extends self::B* = self::B*>(S* s) → dynamic => self::Extension|genericMethod<self::Extension|get#genericMethod::T*, S*>(#this, s);
+static method Extension|genericMethod<T extends self::B*, S extends self::B*>(lowered final self::Class<self::Extension|genericMethod::T*>* #this, self::Extension|genericMethod::S* s) → dynamic {}
+static method Extension|get#genericMethod<T extends self::B*>(lowered final self::Class<self::Extension|get#genericMethod::T*>* #this) → <S extends self::B*>(S*) →* dynamic
+  return <S extends self::B*>(S* s) → dynamic => self::Extension|genericMethod<self::Extension|get#genericMethod::T*, S*>(#this, s);
 static method main() → dynamic {}
 static method test() → dynamic {
   self::A* a;
diff --git a/pkg/front_end/testcases/extensions/check_bounds.dart.weak.outline.expect b/pkg/front_end/testcases/extensions/check_bounds.dart.weak.outline.expect
index b599220..22f598c 100644
--- a/pkg/front_end/testcases/extensions/check_bounds.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/extensions/check_bounds.dart.weak.outline.expect
@@ -21,7 +21,7 @@
   synthetic constructor •() → self::B*
     ;
 }
-class Class<T extends self::A* = self::A*> extends core::Object {
+class Class<T extends self::A*> extends core::Object {
   synthetic constructor •() → self::Class<self::Class::T*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
@@ -35,7 +35,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-extension Extension<T extends self::B* = self::B*> on self::Class<T*>* {
+extension Extension<T extends self::B*> on self::Class<T*>* {
   method method = self::Extension|method;
   tearoff method = self::Extension|get#method;
   method genericMethod = self::Extension|genericMethod;
@@ -73,14 +73,14 @@
 static final field dynamic field27;
 static final field dynamic field28;
 static final field dynamic field29;
-static method Extension|method<T extends self::B* = self::B*>(lowered final self::Class<self::Extension|method::T*>* #this) → dynamic
+static method Extension|method<T extends self::B*>(lowered final self::Class<self::Extension|method::T*>* #this) → dynamic
   ;
-static method Extension|get#method<T extends self::B* = self::B*>(lowered final self::Class<self::Extension|get#method::T*>* #this) → () →* dynamic
+static method Extension|get#method<T extends self::B*>(lowered final self::Class<self::Extension|get#method::T*>* #this) → () →* dynamic
   return () → dynamic => self::Extension|method<self::Extension|get#method::T*>(#this);
-static method Extension|genericMethod<T extends self::B* = self::B*, S extends self::B* = self::B*>(lowered final self::Class<self::Extension|genericMethod::T*>* #this, self::Extension|genericMethod::S* s) → dynamic
+static method Extension|genericMethod<T extends self::B*, S extends self::B*>(lowered final self::Class<self::Extension|genericMethod::T*>* #this, self::Extension|genericMethod::S* s) → dynamic
   ;
-static method Extension|get#genericMethod<T extends self::B* = self::B*>(lowered final self::Class<self::Extension|get#genericMethod::T*>* #this) → <S extends self::B* = self::B*>(S*) →* dynamic
-  return <S extends self::B* = self::B*>(S* s) → dynamic => self::Extension|genericMethod<self::Extension|get#genericMethod::T*, S*>(#this, s);
+static method Extension|get#genericMethod<T extends self::B*>(lowered final self::Class<self::Extension|get#genericMethod::T*>* #this) → <S extends self::B*>(S*) →* dynamic
+  return <S extends self::B*>(S* s) → dynamic => self::Extension|genericMethod<self::Extension|get#genericMethod::T*, S*>(#this, s);
 static method main() → dynamic
   ;
 static method test() → dynamic
diff --git a/pkg/front_end/testcases/extensions/check_bounds.dart.weak.transformed.expect b/pkg/front_end/testcases/extensions/check_bounds.dart.weak.transformed.expect
index 635468b..cef7b3b 100644
--- a/pkg/front_end/testcases/extensions/check_bounds.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/extensions/check_bounds.dart.weak.transformed.expect
@@ -827,7 +827,7 @@
     : super self::A::•()
     ;
 }
-class Class<T extends self::A* = self::A*> extends core::Object {
+class Class<T extends self::A*> extends core::Object {
   synthetic constructor •() → self::Class<self::Class::T*>*
     : super core::Object::•()
     ;
@@ -842,7 +842,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-extension Extension<T extends self::B* = self::B*> on self::Class<T*>* {
+extension Extension<T extends self::B*> on self::Class<T*>* {
   method method = self::Extension|method;
   tearoff method = self::Extension|get#method;
   method genericMethod = self::Extension|genericMethod;
@@ -885,12 +885,12 @@
 static final field dynamic field27 = self::Extension|genericMethod<self::B*, self::A*>(self::classB, self::a);
 static final field dynamic field28 = self::Extension|genericMethod<self::B*, self::A*>(self::classB, self::a);
 static final field dynamic field29 = self::Extension|genericMethod<self::B*, self::B*>(self::classB, self::a as{TypeError} self::B*);
-static method Extension|method<T extends self::B* = self::B*>(lowered final self::Class<self::Extension|method::T*>* #this) → dynamic {}
-static method Extension|get#method<T extends self::B* = self::B*>(lowered final self::Class<self::Extension|get#method::T*>* #this) → () →* dynamic
+static method Extension|method<T extends self::B*>(lowered final self::Class<self::Extension|method::T*>* #this) → dynamic {}
+static method Extension|get#method<T extends self::B*>(lowered final self::Class<self::Extension|get#method::T*>* #this) → () →* dynamic
   return () → dynamic => self::Extension|method<self::Extension|get#method::T*>(#this);
-static method Extension|genericMethod<T extends self::B* = self::B*, S extends self::B* = self::B*>(lowered final self::Class<self::Extension|genericMethod::T*>* #this, self::Extension|genericMethod::S* s) → dynamic {}
-static method Extension|get#genericMethod<T extends self::B* = self::B*>(lowered final self::Class<self::Extension|get#genericMethod::T*>* #this) → <S extends self::B* = self::B*>(S*) →* dynamic
-  return <S extends self::B* = self::B*>(S* s) → dynamic => self::Extension|genericMethod<self::Extension|get#genericMethod::T*, S*>(#this, s);
+static method Extension|genericMethod<T extends self::B*, S extends self::B*>(lowered final self::Class<self::Extension|genericMethod::T*>* #this, self::Extension|genericMethod::S* s) → dynamic {}
+static method Extension|get#genericMethod<T extends self::B*>(lowered final self::Class<self::Extension|get#genericMethod::T*>* #this) → <S extends self::B*>(S*) →* dynamic
+  return <S extends self::B*>(S* s) → dynamic => self::Extension|genericMethod<self::Extension|get#genericMethod::T*, S*>(#this, s);
 static method main() → dynamic {}
 static method test() → dynamic {
   self::A* a;
diff --git a/pkg/front_end/testcases/extensions/explicit_extension_access.dart.weak.expect b/pkg/front_end/testcases/extensions/explicit_extension_access.dart.weak.expect
index c216317..cf95acc 100644
--- a/pkg/front_end/testcases/extensions/explicit_extension_access.dart.weak.expect
+++ b/pkg/front_end/testcases/extensions/explicit_extension_access.dart.weak.expect
@@ -44,10 +44,10 @@
   return #this.{self::Class::field1};
 static method Extension1|get#method(lowered final self::Class* #this) → () →* core::int*
   return () → core::int* => self::Extension1|method(#this);
-static method Extension1|genericMethod<T extends core::num* = core::num*>(lowered final self::Class* #this, self::Extension1|genericMethod::T* t) → core::int*
+static method Extension1|genericMethod<T extends core::num*>(lowered final self::Class* #this, self::Extension1|genericMethod::T* t) → core::int*
   return #this.{self::Class::field1}.{core::num::+}(t) as{TypeError} core::int*;
-static method Extension1|get#genericMethod(lowered final self::Class* #this) → <T extends core::num* = core::num*>(T*) →* core::int*
-  return <T extends core::num* = core::num*>(T* t) → core::int* => self::Extension1|genericMethod<T*>(#this, t);
+static method Extension1|get#genericMethod(lowered final self::Class* #this) → <T extends core::num*>(T*) →* core::int*
+  return <T extends core::num*>(T* t) → core::int* => self::Extension1|genericMethod<T*>(#this, t);
 static method Extension2|get#field(lowered final self::Class* #this) → core::int*
   return #this.{self::Class::field2};
 static method Extension2|set#field(lowered final self::Class* #this, core::int* value) → void {
@@ -57,10 +57,10 @@
   return #this.{self::Class::field2};
 static method Extension2|get#method(lowered final self::Class* #this) → () →* core::int*
   return () → core::int* => self::Extension2|method(#this);
-static method Extension2|genericMethod<T extends core::num* = core::num*>(lowered final self::Class* #this, self::Extension2|genericMethod::T* t) → core::int*
+static method Extension2|genericMethod<T extends core::num*>(lowered final self::Class* #this, self::Extension2|genericMethod::T* t) → core::int*
   return #this.{self::Class::field2}.{core::num::+}(t) as{TypeError} core::int*;
-static method Extension2|get#genericMethod(lowered final self::Class* #this) → <T extends core::num* = core::num*>(T*) →* core::int*
-  return <T extends core::num* = core::num*>(T* t) → core::int* => self::Extension2|genericMethod<T*>(#this, t);
+static method Extension2|get#genericMethod(lowered final self::Class* #this) → <T extends core::num*>(T*) →* core::int*
+  return <T extends core::num*>(T* t) → core::int* => self::Extension2|genericMethod<T*>(#this, t);
 static method main() → dynamic {
   self::Class* c = new self::Class::•();
   self::expect(42, self::Extension1|get#field(c));
@@ -75,8 +75,8 @@
   self::expect(97, self::Extension2|genericMethod<core::int*>(c, 10));
   self::expect(52, self::Extension1|genericMethod<core::num*>(c, 10));
   self::expect(97, self::Extension2|genericMethod<core::num*>(c, 10));
-  <T extends core::num* = core::num*>(T*) →* core::int* genericTearOff1 = self::Extension1|get#genericMethod(c);
-  <T extends core::num* = core::num*>(T*) →* core::int* genericTearOff2 = self::Extension2|get#genericMethod(c);
+  <T extends core::num*>(T*) →* core::int* genericTearOff1 = self::Extension1|get#genericMethod(c);
+  <T extends core::num*>(T*) →* core::int* genericTearOff2 = self::Extension2|get#genericMethod(c);
   self::expect(52, genericTearOff1.call<core::int*>(10));
   self::expect(97, genericTearOff2.call<core::int*>(10));
   self::expect(52, genericTearOff1.call<core::num*>(10));
diff --git a/pkg/front_end/testcases/extensions/explicit_extension_access.dart.weak.outline.expect b/pkg/front_end/testcases/extensions/explicit_extension_access.dart.weak.outline.expect
index c567e2c..a5c90f6 100644
--- a/pkg/front_end/testcases/extensions/explicit_extension_access.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/extensions/explicit_extension_access.dart.weak.outline.expect
@@ -42,10 +42,10 @@
   ;
 static method Extension1|get#method(lowered final self::Class* #this) → () →* core::int*
   return () → core::int* => self::Extension1|method(#this);
-static method Extension1|genericMethod<T extends core::num* = core::num*>(lowered final self::Class* #this, self::Extension1|genericMethod::T* t) → core::int*
+static method Extension1|genericMethod<T extends core::num*>(lowered final self::Class* #this, self::Extension1|genericMethod::T* t) → core::int*
   ;
-static method Extension1|get#genericMethod(lowered final self::Class* #this) → <T extends core::num* = core::num*>(T*) →* core::int*
-  return <T extends core::num* = core::num*>(T* t) → core::int* => self::Extension1|genericMethod<T*>(#this, t);
+static method Extension1|get#genericMethod(lowered final self::Class* #this) → <T extends core::num*>(T*) →* core::int*
+  return <T extends core::num*>(T* t) → core::int* => self::Extension1|genericMethod<T*>(#this, t);
 static method Extension2|get#field(lowered final self::Class* #this) → core::int*
   ;
 static method Extension2|set#field(lowered final self::Class* #this, core::int* value) → void
@@ -54,10 +54,10 @@
   ;
 static method Extension2|get#method(lowered final self::Class* #this) → () →* core::int*
   return () → core::int* => self::Extension2|method(#this);
-static method Extension2|genericMethod<T extends core::num* = core::num*>(lowered final self::Class* #this, self::Extension2|genericMethod::T* t) → core::int*
+static method Extension2|genericMethod<T extends core::num*>(lowered final self::Class* #this, self::Extension2|genericMethod::T* t) → core::int*
   ;
-static method Extension2|get#genericMethod(lowered final self::Class* #this) → <T extends core::num* = core::num*>(T*) →* core::int*
-  return <T extends core::num* = core::num*>(T* t) → core::int* => self::Extension2|genericMethod<T*>(#this, t);
+static method Extension2|get#genericMethod(lowered final self::Class* #this) → <T extends core::num*>(T*) →* core::int*
+  return <T extends core::num*>(T* t) → core::int* => self::Extension2|genericMethod<T*>(#this, t);
 static method main() → dynamic
   ;
 static method expect(dynamic expected, dynamic actual) → dynamic
diff --git a/pkg/front_end/testcases/extensions/explicit_extension_access.dart.weak.transformed.expect b/pkg/front_end/testcases/extensions/explicit_extension_access.dart.weak.transformed.expect
index e1fd4f1..ad97e80 100644
--- a/pkg/front_end/testcases/extensions/explicit_extension_access.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/extensions/explicit_extension_access.dart.weak.transformed.expect
@@ -44,10 +44,10 @@
   return #this.{self::Class::field1};
 static method Extension1|get#method(lowered final self::Class* #this) → () →* core::int*
   return () → core::int* => self::Extension1|method(#this);
-static method Extension1|genericMethod<T extends core::num* = core::num*>(lowered final self::Class* #this, self::Extension1|genericMethod::T* t) → core::int*
+static method Extension1|genericMethod<T extends core::num*>(lowered final self::Class* #this, self::Extension1|genericMethod::T* t) → core::int*
   return #this.{self::Class::field1}.{core::num::+}(t) as{TypeError} core::int*;
-static method Extension1|get#genericMethod(lowered final self::Class* #this) → <T extends core::num* = core::num*>(T*) →* core::int*
-  return <T extends core::num* = core::num*>(T* t) → core::int* => self::Extension1|genericMethod<T*>(#this, t);
+static method Extension1|get#genericMethod(lowered final self::Class* #this) → <T extends core::num*>(T*) →* core::int*
+  return <T extends core::num*>(T* t) → core::int* => self::Extension1|genericMethod<T*>(#this, t);
 static method Extension2|get#field(lowered final self::Class* #this) → core::int*
   return #this.{self::Class::field2};
 static method Extension2|set#field(lowered final self::Class* #this, core::int* value) → void {
@@ -57,10 +57,10 @@
   return #this.{self::Class::field2};
 static method Extension2|get#method(lowered final self::Class* #this) → () →* core::int*
   return () → core::int* => self::Extension2|method(#this);
-static method Extension2|genericMethod<T extends core::num* = core::num*>(lowered final self::Class* #this, self::Extension2|genericMethod::T* t) → core::int*
+static method Extension2|genericMethod<T extends core::num*>(lowered final self::Class* #this, self::Extension2|genericMethod::T* t) → core::int*
   return #this.{self::Class::field2}.{core::num::+}(t) as{TypeError} core::int*;
-static method Extension2|get#genericMethod(lowered final self::Class* #this) → <T extends core::num* = core::num*>(T*) →* core::int*
-  return <T extends core::num* = core::num*>(T* t) → core::int* => self::Extension2|genericMethod<T*>(#this, t);
+static method Extension2|get#genericMethod(lowered final self::Class* #this) → <T extends core::num*>(T*) →* core::int*
+  return <T extends core::num*>(T* t) → core::int* => self::Extension2|genericMethod<T*>(#this, t);
 static method main() → dynamic {
   self::Class* c = new self::Class::•();
   self::expect(42, self::Extension1|get#field(c));
@@ -75,8 +75,8 @@
   self::expect(97, self::Extension2|genericMethod<core::int*>(c, 10));
   self::expect(52, self::Extension1|genericMethod<core::num*>(c, 10));
   self::expect(97, self::Extension2|genericMethod<core::num*>(c, 10));
-  <T extends core::num* = core::num*>(T*) →* core::int* genericTearOff1 = self::Extension1|get#genericMethod(c);
-  <T extends core::num* = core::num*>(T*) →* core::int* genericTearOff2 = self::Extension2|get#genericMethod(c);
+  <T extends core::num*>(T*) →* core::int* genericTearOff1 = self::Extension1|get#genericMethod(c);
+  <T extends core::num*>(T*) →* core::int* genericTearOff2 = self::Extension2|get#genericMethod(c);
   self::expect(52, genericTearOff1.call<core::int*>(10));
   self::expect(97, genericTearOff2.call<core::int*>(10));
   self::expect(52, genericTearOff1.call<core::num*>(10));
diff --git a/pkg/front_end/testcases/extensions/explicit_generic_extension_access.dart.weak.expect b/pkg/front_end/testcases/extensions/explicit_generic_extension_access.dart.weak.expect
index 1934541..6cff7c7 100644
--- a/pkg/front_end/testcases/extensions/explicit_generic_extension_access.dart.weak.expect
+++ b/pkg/front_end/testcases/extensions/explicit_generic_extension_access.dart.weak.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class Class<T extends core::num* = core::num*> extends core::Object {
+class Class<T extends core::num*> extends core::Object {
   generic-covariant-impl field self::Class::T* field1;
   generic-covariant-impl field self::Class::T* field2;
   constructor •(self::Class::T* field1, self::Class::T* field2) → self::Class<self::Class::T*>*
@@ -19,7 +19,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-extension Extension1<T extends core::num* = core::num*> on self::Class<T*>* {
+extension Extension1<T extends core::num*> on self::Class<T*>* {
   static field latestType = self::Extension1|latestType;
   get field = self::Extension1|get#field;
   method method = self::Extension1|method;
@@ -28,7 +28,7 @@
   tearoff genericMethod = self::Extension1|get#genericMethod;
   set field = self::Extension1|set#field;
 }
-extension Extension2<T extends core::num* = core::num*> on self::Class<T*>* {
+extension Extension2<T extends core::num*> on self::Class<T*>* {
   get field = self::Extension2|get#field;
   method method = self::Extension2|method;
   tearoff method = self::Extension2|get#method;
@@ -37,39 +37,39 @@
   set field = self::Extension2|set#field;
 }
 static field core::String* Extension1|latestType;
-static method Extension1|get#field<T extends core::num* = core::num*>(lowered final self::Class<self::Extension1|get#field::T*>* #this) → self::Extension1|get#field::T* {
+static method Extension1|get#field<T extends core::num*>(lowered final self::Class<self::Extension1|get#field::T*>* #this) → self::Extension1|get#field::T* {
   self::Extension1|latestType = "${self::Extension1|get#field::T*}";
   return #this.{self::Class::field1};
 }
-static method Extension1|set#field<T extends core::num* = core::num*>(lowered final self::Class<self::Extension1|set#field::T*>* #this, self::Extension1|set#field::T* value) → void {
+static method Extension1|set#field<T extends core::num*>(lowered final self::Class<self::Extension1|set#field::T*>* #this, self::Extension1|set#field::T* value) → void {
   self::Extension1|latestType = "${self::Extension1|set#field::T*}";
   #this.{self::Class::field1} = value;
 }
-static method Extension1|method<T extends core::num* = core::num*>(lowered final self::Class<self::Extension1|method::T*>* #this) → self::Extension1|method::T* {
+static method Extension1|method<T extends core::num*>(lowered final self::Class<self::Extension1|method::T*>* #this) → self::Extension1|method::T* {
   self::Extension1|latestType = "${self::Extension1|method::T*}";
   return #this.{self::Class::field1};
 }
-static method Extension1|get#method<T extends core::num* = core::num*>(lowered final self::Class<self::Extension1|get#method::T*>* #this) → () →* self::Extension1|get#method::T*
+static method Extension1|get#method<T extends core::num*>(lowered final self::Class<self::Extension1|get#method::T*>* #this) → () →* self::Extension1|get#method::T*
   return () → self::Extension1|get#method::T* => self::Extension1|method<self::Extension1|get#method::T*>(#this);
-static method Extension1|genericMethod<T extends core::num* = core::num*, S extends core::num* = core::num*>(lowered final self::Class<self::Extension1|genericMethod::T*>* #this, self::Extension1|genericMethod::S* t) → self::Extension1|genericMethod::T* {
+static method Extension1|genericMethod<T extends core::num*, S extends core::num*>(lowered final self::Class<self::Extension1|genericMethod::T*>* #this, self::Extension1|genericMethod::S* t) → self::Extension1|genericMethod::T* {
   self::Extension1|latestType = "${self::Extension1|genericMethod::T*}:${self::Extension1|genericMethod::S*}";
   return #this.{self::Class::field1}.{core::num::+}(t) as{TypeError} self::Extension1|genericMethod::T*;
 }
-static method Extension1|get#genericMethod<T extends core::num* = core::num*>(lowered final self::Class<self::Extension1|get#genericMethod::T*>* #this) → <S extends core::num* = core::num*>(S*) →* self::Extension1|get#genericMethod::T*
-  return <S extends core::num* = core::num*>(S* t) → self::Extension1|get#genericMethod::T* => self::Extension1|genericMethod<self::Extension1|get#genericMethod::T*, S*>(#this, t);
-static method Extension2|get#field<T extends core::num* = core::num*>(lowered final self::Class<self::Extension2|get#field::T*>* #this) → self::Extension2|get#field::T*
+static method Extension1|get#genericMethod<T extends core::num*>(lowered final self::Class<self::Extension1|get#genericMethod::T*>* #this) → <S extends core::num*>(S*) →* self::Extension1|get#genericMethod::T*
+  return <S extends core::num*>(S* t) → self::Extension1|get#genericMethod::T* => self::Extension1|genericMethod<self::Extension1|get#genericMethod::T*, S*>(#this, t);
+static method Extension2|get#field<T extends core::num*>(lowered final self::Class<self::Extension2|get#field::T*>* #this) → self::Extension2|get#field::T*
   return #this.{self::Class::field2};
-static method Extension2|set#field<T extends core::num* = core::num*>(lowered final self::Class<self::Extension2|set#field::T*>* #this, self::Extension2|set#field::T* value) → void {
+static method Extension2|set#field<T extends core::num*>(lowered final self::Class<self::Extension2|set#field::T*>* #this, self::Extension2|set#field::T* value) → void {
   #this.{self::Class::field2} = value;
 }
-static method Extension2|method<T extends core::num* = core::num*>(lowered final self::Class<self::Extension2|method::T*>* #this) → self::Extension2|method::T*
+static method Extension2|method<T extends core::num*>(lowered final self::Class<self::Extension2|method::T*>* #this) → self::Extension2|method::T*
   return #this.{self::Class::field2};
-static method Extension2|get#method<T extends core::num* = core::num*>(lowered final self::Class<self::Extension2|get#method::T*>* #this) → () →* self::Extension2|get#method::T*
+static method Extension2|get#method<T extends core::num*>(lowered final self::Class<self::Extension2|get#method::T*>* #this) → () →* self::Extension2|get#method::T*
   return () → self::Extension2|get#method::T* => self::Extension2|method<self::Extension2|get#method::T*>(#this);
-static method Extension2|genericMethod<T extends core::num* = core::num*, S extends core::num* = core::num*>(lowered final self::Class<self::Extension2|genericMethod::T*>* #this, self::Extension2|genericMethod::S* t) → self::Extension2|genericMethod::T*
+static method Extension2|genericMethod<T extends core::num*, S extends core::num*>(lowered final self::Class<self::Extension2|genericMethod::T*>* #this, self::Extension2|genericMethod::S* t) → self::Extension2|genericMethod::T*
   return #this.{self::Class::field2}.{core::num::+}(t) as{TypeError} self::Extension2|genericMethod::T*;
-static method Extension2|get#genericMethod<T extends core::num* = core::num*>(lowered final self::Class<self::Extension2|get#genericMethod::T*>* #this) → <S extends core::num* = core::num*>(S*) →* self::Extension2|get#genericMethod::T*
-  return <S extends core::num* = core::num*>(S* t) → self::Extension2|get#genericMethod::T* => self::Extension2|genericMethod<self::Extension2|get#genericMethod::T*, S*>(#this, t);
+static method Extension2|get#genericMethod<T extends core::num*>(lowered final self::Class<self::Extension2|get#genericMethod::T*>* #this) → <S extends core::num*>(S*) →* self::Extension2|get#genericMethod::T*
+  return <S extends core::num*>(S* t) → self::Extension2|get#genericMethod::T* => self::Extension2|genericMethod<self::Extension2|get#genericMethod::T*, S*>(#this, t);
 static method main() → dynamic {
   self::Class<core::int*>* c = new self::Class::•<core::int*>(42, 87);
   self::expect(42, self::Extension1|get#field<core::num*>(c));
@@ -106,9 +106,9 @@
   self::expect("int:num", self::Extension1|latestType);
   self::expect(52, self::Extension1|genericMethod<core::int*, core::int*>(c, 10));
   self::expect("int:int", self::Extension1|latestType);
-  <S extends core::num* = core::num*>(S*) →* core::num* genericTearOffNumber1 = self::Extension1|get#genericMethod<core::num*>(c);
-  <S extends core::num* = core::num*>(S*) →* core::int* genericTearOffInteger1 = self::Extension1|get#genericMethod<core::int*>(c);
-  <S extends core::num* = core::num*>(S*) →* core::num* genericTearOff2 = self::Extension2|get#genericMethod<core::num*>(c);
+  <S extends core::num*>(S*) →* core::num* genericTearOffNumber1 = self::Extension1|get#genericMethod<core::num*>(c);
+  <S extends core::num*>(S*) →* core::int* genericTearOffInteger1 = self::Extension1|get#genericMethod<core::int*>(c);
+  <S extends core::num*>(S*) →* core::num* genericTearOff2 = self::Extension2|get#genericMethod<core::num*>(c);
   self::expect(52, genericTearOffNumber1.call<core::int*>(10));
   self::expect("num:int", self::Extension1|latestType);
   self::expect(52, genericTearOffInteger1.call<core::int*>(10));
diff --git a/pkg/front_end/testcases/extensions/explicit_generic_extension_access.dart.weak.outline.expect b/pkg/front_end/testcases/extensions/explicit_generic_extension_access.dart.weak.outline.expect
index 633ea25..54e9504 100644
--- a/pkg/front_end/testcases/extensions/explicit_generic_extension_access.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/extensions/explicit_generic_extension_access.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class Class<T extends core::num* = core::num*> extends core::Object {
+class Class<T extends core::num*> extends core::Object {
   generic-covariant-impl field self::Class::T* field1;
   generic-covariant-impl field self::Class::T* field2;
   constructor •(self::Class::T* field1, self::Class::T* field2) → self::Class<self::Class::T*>*
@@ -18,7 +18,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-extension Extension1<T extends core::num* = core::num*> on self::Class<T*>* {
+extension Extension1<T extends core::num*> on self::Class<T*>* {
   static field latestType = self::Extension1|latestType;
   get field = self::Extension1|get#field;
   method method = self::Extension1|method;
@@ -27,7 +27,7 @@
   tearoff genericMethod = self::Extension1|get#genericMethod;
   set field = self::Extension1|set#field;
 }
-extension Extension2<T extends core::num* = core::num*> on self::Class<T*>* {
+extension Extension2<T extends core::num*> on self::Class<T*>* {
   get field = self::Extension2|get#field;
   method method = self::Extension2|method;
   tearoff method = self::Extension2|get#method;
@@ -36,30 +36,30 @@
   set field = self::Extension2|set#field;
 }
 static field core::String* Extension1|latestType;
-static method Extension1|get#field<T extends core::num* = core::num*>(lowered final self::Class<self::Extension1|get#field::T*>* #this) → self::Extension1|get#field::T*
+static method Extension1|get#field<T extends core::num*>(lowered final self::Class<self::Extension1|get#field::T*>* #this) → self::Extension1|get#field::T*
   ;
-static method Extension1|set#field<T extends core::num* = core::num*>(lowered final self::Class<self::Extension1|set#field::T*>* #this, self::Extension1|set#field::T* value) → void
+static method Extension1|set#field<T extends core::num*>(lowered final self::Class<self::Extension1|set#field::T*>* #this, self::Extension1|set#field::T* value) → void
   ;
-static method Extension1|method<T extends core::num* = core::num*>(lowered final self::Class<self::Extension1|method::T*>* #this) → self::Extension1|method::T*
+static method Extension1|method<T extends core::num*>(lowered final self::Class<self::Extension1|method::T*>* #this) → self::Extension1|method::T*
   ;
-static method Extension1|get#method<T extends core::num* = core::num*>(lowered final self::Class<self::Extension1|get#method::T*>* #this) → () →* self::Extension1|get#method::T*
+static method Extension1|get#method<T extends core::num*>(lowered final self::Class<self::Extension1|get#method::T*>* #this) → () →* self::Extension1|get#method::T*
   return () → self::Extension1|get#method::T* => self::Extension1|method<self::Extension1|get#method::T*>(#this);
-static method Extension1|genericMethod<T extends core::num* = core::num*, S extends core::num* = core::num*>(lowered final self::Class<self::Extension1|genericMethod::T*>* #this, self::Extension1|genericMethod::S* t) → self::Extension1|genericMethod::T*
+static method Extension1|genericMethod<T extends core::num*, S extends core::num*>(lowered final self::Class<self::Extension1|genericMethod::T*>* #this, self::Extension1|genericMethod::S* t) → self::Extension1|genericMethod::T*
   ;
-static method Extension1|get#genericMethod<T extends core::num* = core::num*>(lowered final self::Class<self::Extension1|get#genericMethod::T*>* #this) → <S extends core::num* = core::num*>(S*) →* self::Extension1|get#genericMethod::T*
-  return <S extends core::num* = core::num*>(S* t) → self::Extension1|get#genericMethod::T* => self::Extension1|genericMethod<self::Extension1|get#genericMethod::T*, S*>(#this, t);
-static method Extension2|get#field<T extends core::num* = core::num*>(lowered final self::Class<self::Extension2|get#field::T*>* #this) → self::Extension2|get#field::T*
+static method Extension1|get#genericMethod<T extends core::num*>(lowered final self::Class<self::Extension1|get#genericMethod::T*>* #this) → <S extends core::num*>(S*) →* self::Extension1|get#genericMethod::T*
+  return <S extends core::num*>(S* t) → self::Extension1|get#genericMethod::T* => self::Extension1|genericMethod<self::Extension1|get#genericMethod::T*, S*>(#this, t);
+static method Extension2|get#field<T extends core::num*>(lowered final self::Class<self::Extension2|get#field::T*>* #this) → self::Extension2|get#field::T*
   ;
-static method Extension2|set#field<T extends core::num* = core::num*>(lowered final self::Class<self::Extension2|set#field::T*>* #this, self::Extension2|set#field::T* value) → void
+static method Extension2|set#field<T extends core::num*>(lowered final self::Class<self::Extension2|set#field::T*>* #this, self::Extension2|set#field::T* value) → void
   ;
-static method Extension2|method<T extends core::num* = core::num*>(lowered final self::Class<self::Extension2|method::T*>* #this) → self::Extension2|method::T*
+static method Extension2|method<T extends core::num*>(lowered final self::Class<self::Extension2|method::T*>* #this) → self::Extension2|method::T*
   ;
-static method Extension2|get#method<T extends core::num* = core::num*>(lowered final self::Class<self::Extension2|get#method::T*>* #this) → () →* self::Extension2|get#method::T*
+static method Extension2|get#method<T extends core::num*>(lowered final self::Class<self::Extension2|get#method::T*>* #this) → () →* self::Extension2|get#method::T*
   return () → self::Extension2|get#method::T* => self::Extension2|method<self::Extension2|get#method::T*>(#this);
-static method Extension2|genericMethod<T extends core::num* = core::num*, S extends core::num* = core::num*>(lowered final self::Class<self::Extension2|genericMethod::T*>* #this, self::Extension2|genericMethod::S* t) → self::Extension2|genericMethod::T*
+static method Extension2|genericMethod<T extends core::num*, S extends core::num*>(lowered final self::Class<self::Extension2|genericMethod::T*>* #this, self::Extension2|genericMethod::S* t) → self::Extension2|genericMethod::T*
   ;
-static method Extension2|get#genericMethod<T extends core::num* = core::num*>(lowered final self::Class<self::Extension2|get#genericMethod::T*>* #this) → <S extends core::num* = core::num*>(S*) →* self::Extension2|get#genericMethod::T*
-  return <S extends core::num* = core::num*>(S* t) → self::Extension2|get#genericMethod::T* => self::Extension2|genericMethod<self::Extension2|get#genericMethod::T*, S*>(#this, t);
+static method Extension2|get#genericMethod<T extends core::num*>(lowered final self::Class<self::Extension2|get#genericMethod::T*>* #this) → <S extends core::num*>(S*) →* self::Extension2|get#genericMethod::T*
+  return <S extends core::num*>(S* t) → self::Extension2|get#genericMethod::T* => self::Extension2|genericMethod<self::Extension2|get#genericMethod::T*, S*>(#this, t);
 static method main() → dynamic
   ;
 static method expect(dynamic expected, dynamic actual) → dynamic
diff --git a/pkg/front_end/testcases/extensions/explicit_generic_extension_access.dart.weak.transformed.expect b/pkg/front_end/testcases/extensions/explicit_generic_extension_access.dart.weak.transformed.expect
index c99297a..8f41bf6 100644
--- a/pkg/front_end/testcases/extensions/explicit_generic_extension_access.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/extensions/explicit_generic_extension_access.dart.weak.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class Class<T extends core::num* = core::num*> extends core::Object {
+class Class<T extends core::num*> extends core::Object {
   generic-covariant-impl field self::Class::T* field1;
   generic-covariant-impl field self::Class::T* field2;
   constructor •(self::Class::T* field1, self::Class::T* field2) → self::Class<self::Class::T*>*
@@ -19,7 +19,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-extension Extension1<T extends core::num* = core::num*> on self::Class<T*>* {
+extension Extension1<T extends core::num*> on self::Class<T*>* {
   static field latestType = self::Extension1|latestType;
   get field = self::Extension1|get#field;
   method method = self::Extension1|method;
@@ -28,7 +28,7 @@
   tearoff genericMethod = self::Extension1|get#genericMethod;
   set field = self::Extension1|set#field;
 }
-extension Extension2<T extends core::num* = core::num*> on self::Class<T*>* {
+extension Extension2<T extends core::num*> on self::Class<T*>* {
   get field = self::Extension2|get#field;
   method method = self::Extension2|method;
   tearoff method = self::Extension2|get#method;
@@ -37,39 +37,39 @@
   set field = self::Extension2|set#field;
 }
 static field core::String* Extension1|latestType;
-static method Extension1|get#field<T extends core::num* = core::num*>(lowered final self::Class<self::Extension1|get#field::T*>* #this) → self::Extension1|get#field::T* {
+static method Extension1|get#field<T extends core::num*>(lowered final self::Class<self::Extension1|get#field::T*>* #this) → self::Extension1|get#field::T* {
   self::Extension1|latestType = "${self::Extension1|get#field::T*}";
   return #this.{self::Class::field1};
 }
-static method Extension1|set#field<T extends core::num* = core::num*>(lowered final self::Class<self::Extension1|set#field::T*>* #this, self::Extension1|set#field::T* value) → void {
+static method Extension1|set#field<T extends core::num*>(lowered final self::Class<self::Extension1|set#field::T*>* #this, self::Extension1|set#field::T* value) → void {
   self::Extension1|latestType = "${self::Extension1|set#field::T*}";
   #this.{self::Class::field1} = value;
 }
-static method Extension1|method<T extends core::num* = core::num*>(lowered final self::Class<self::Extension1|method::T*>* #this) → self::Extension1|method::T* {
+static method Extension1|method<T extends core::num*>(lowered final self::Class<self::Extension1|method::T*>* #this) → self::Extension1|method::T* {
   self::Extension1|latestType = "${self::Extension1|method::T*}";
   return #this.{self::Class::field1};
 }
-static method Extension1|get#method<T extends core::num* = core::num*>(lowered final self::Class<self::Extension1|get#method::T*>* #this) → () →* self::Extension1|get#method::T*
+static method Extension1|get#method<T extends core::num*>(lowered final self::Class<self::Extension1|get#method::T*>* #this) → () →* self::Extension1|get#method::T*
   return () → self::Extension1|get#method::T* => self::Extension1|method<self::Extension1|get#method::T*>(#this);
-static method Extension1|genericMethod<T extends core::num* = core::num*, S extends core::num* = core::num*>(lowered final self::Class<self::Extension1|genericMethod::T*>* #this, self::Extension1|genericMethod::S* t) → self::Extension1|genericMethod::T* {
+static method Extension1|genericMethod<T extends core::num*, S extends core::num*>(lowered final self::Class<self::Extension1|genericMethod::T*>* #this, self::Extension1|genericMethod::S* t) → self::Extension1|genericMethod::T* {
   self::Extension1|latestType = "${self::Extension1|genericMethod::T*}:${self::Extension1|genericMethod::S*}";
   return #this.{self::Class::field1}.{core::num::+}(t) as{TypeError} self::Extension1|genericMethod::T*;
 }
-static method Extension1|get#genericMethod<T extends core::num* = core::num*>(lowered final self::Class<self::Extension1|get#genericMethod::T*>* #this) → <S extends core::num* = core::num*>(S*) →* self::Extension1|get#genericMethod::T*
-  return <S extends core::num* = core::num*>(S* t) → self::Extension1|get#genericMethod::T* => self::Extension1|genericMethod<self::Extension1|get#genericMethod::T*, S*>(#this, t);
-static method Extension2|get#field<T extends core::num* = core::num*>(lowered final self::Class<self::Extension2|get#field::T*>* #this) → self::Extension2|get#field::T*
+static method Extension1|get#genericMethod<T extends core::num*>(lowered final self::Class<self::Extension1|get#genericMethod::T*>* #this) → <S extends core::num*>(S*) →* self::Extension1|get#genericMethod::T*
+  return <S extends core::num*>(S* t) → self::Extension1|get#genericMethod::T* => self::Extension1|genericMethod<self::Extension1|get#genericMethod::T*, S*>(#this, t);
+static method Extension2|get#field<T extends core::num*>(lowered final self::Class<self::Extension2|get#field::T*>* #this) → self::Extension2|get#field::T*
   return #this.{self::Class::field2};
-static method Extension2|set#field<T extends core::num* = core::num*>(lowered final self::Class<self::Extension2|set#field::T*>* #this, self::Extension2|set#field::T* value) → void {
+static method Extension2|set#field<T extends core::num*>(lowered final self::Class<self::Extension2|set#field::T*>* #this, self::Extension2|set#field::T* value) → void {
   #this.{self::Class::field2} = value;
 }
-static method Extension2|method<T extends core::num* = core::num*>(lowered final self::Class<self::Extension2|method::T*>* #this) → self::Extension2|method::T*
+static method Extension2|method<T extends core::num*>(lowered final self::Class<self::Extension2|method::T*>* #this) → self::Extension2|method::T*
   return #this.{self::Class::field2};
-static method Extension2|get#method<T extends core::num* = core::num*>(lowered final self::Class<self::Extension2|get#method::T*>* #this) → () →* self::Extension2|get#method::T*
+static method Extension2|get#method<T extends core::num*>(lowered final self::Class<self::Extension2|get#method::T*>* #this) → () →* self::Extension2|get#method::T*
   return () → self::Extension2|get#method::T* => self::Extension2|method<self::Extension2|get#method::T*>(#this);
-static method Extension2|genericMethod<T extends core::num* = core::num*, S extends core::num* = core::num*>(lowered final self::Class<self::Extension2|genericMethod::T*>* #this, self::Extension2|genericMethod::S* t) → self::Extension2|genericMethod::T*
+static method Extension2|genericMethod<T extends core::num*, S extends core::num*>(lowered final self::Class<self::Extension2|genericMethod::T*>* #this, self::Extension2|genericMethod::S* t) → self::Extension2|genericMethod::T*
   return #this.{self::Class::field2}.{core::num::+}(t) as{TypeError} self::Extension2|genericMethod::T*;
-static method Extension2|get#genericMethod<T extends core::num* = core::num*>(lowered final self::Class<self::Extension2|get#genericMethod::T*>* #this) → <S extends core::num* = core::num*>(S*) →* self::Extension2|get#genericMethod::T*
-  return <S extends core::num* = core::num*>(S* t) → self::Extension2|get#genericMethod::T* => self::Extension2|genericMethod<self::Extension2|get#genericMethod::T*, S*>(#this, t);
+static method Extension2|get#genericMethod<T extends core::num*>(lowered final self::Class<self::Extension2|get#genericMethod::T*>* #this) → <S extends core::num*>(S*) →* self::Extension2|get#genericMethod::T*
+  return <S extends core::num*>(S* t) → self::Extension2|get#genericMethod::T* => self::Extension2|genericMethod<self::Extension2|get#genericMethod::T*, S*>(#this, t);
 static method main() → dynamic {
   self::Class<core::int*>* c = new self::Class::•<core::int*>(42, 87);
   self::expect(42, self::Extension1|get#field<core::num*>(c));
@@ -106,9 +106,9 @@
   self::expect("int:num", self::Extension1|latestType);
   self::expect(52, self::Extension1|genericMethod<core::int*, core::int*>(c, 10));
   self::expect("int:int", self::Extension1|latestType);
-  <S extends core::num* = core::num*>(S*) →* core::num* genericTearOffNumber1 = self::Extension1|get#genericMethod<core::num*>(c);
-  <S extends core::num* = core::num*>(S*) →* core::int* genericTearOffInteger1 = self::Extension1|get#genericMethod<core::int*>(c);
-  <S extends core::num* = core::num*>(S*) →* core::num* genericTearOff2 = self::Extension2|get#genericMethod<core::num*>(c);
+  <S extends core::num*>(S*) →* core::num* genericTearOffNumber1 = self::Extension1|get#genericMethod<core::num*>(c);
+  <S extends core::num*>(S*) →* core::int* genericTearOffInteger1 = self::Extension1|get#genericMethod<core::int*>(c);
+  <S extends core::num*>(S*) →* core::num* genericTearOff2 = self::Extension2|get#genericMethod<core::num*>(c);
   self::expect(52, genericTearOffNumber1.call<core::int*>(10));
   self::expect("num:int", self::Extension1|latestType);
   self::expect(52, genericTearOffInteger1.call<core::int*>(10));
diff --git a/pkg/front_end/testcases/extensions/instance_access.dart.weak.expect b/pkg/front_end/testcases/extensions/instance_access.dart.weak.expect
index 4fd4d22..acfd4c8 100644
--- a/pkg/front_end/testcases/extensions/instance_access.dart.weak.expect
+++ b/pkg/front_end/testcases/extensions/instance_access.dart.weak.expect
@@ -58,12 +58,12 @@
 }
 static method Extension1|get#method(lowered final self::Class1* #this) → () →* core::int*
   return () → core::int* => self::Extension1|method(#this);
-static method Extension1|genericMethod<T extends core::num* = core::num*>(lowered final self::Class1* #this, self::Extension1|genericMethod::T* t) → core::int* {
+static method Extension1|genericMethod<T extends core::num*>(lowered final self::Class1* #this, self::Extension1|genericMethod::T* t) → core::int* {
   core::print("Extension1.genericMethod<${self::Extension1|genericMethod::T*}>(${t}) on ${#this}");
   return #this.{self::Class1::field}.{core::num::+}(t) as{TypeError} core::int*;
 }
-static method Extension1|get#genericMethod(lowered final self::Class1* #this) → <T extends core::num* = core::num*>(T*) →* core::int*
-  return <T extends core::num* = core::num*>(T* t) → core::int* => self::Extension1|genericMethod<T*>(#this, t);
+static method Extension1|get#genericMethod(lowered final self::Class1* #this) → <T extends core::num*>(T*) →* core::int*
+  return <T extends core::num*>(T* t) → core::int* => self::Extension1|genericMethod<T*>(#this, t);
 static method Extension1|get#property(lowered final self::Class1* #this) → core::int* {
   core::print("Extension1.property get on ${#this}");
   return #this.{self::Class1::field};
@@ -79,12 +79,12 @@
 }
 static method Extension2|get#method(lowered final self::Class2* #this) → () →* core::int*
   return () → core::int* => self::Extension2|method(#this);
-static method Extension2|genericMethod<T extends core::num* = core::num*>(lowered final self::Class2* #this, self::Extension2|genericMethod::T* t) → core::int* {
+static method Extension2|genericMethod<T extends core::num*>(lowered final self::Class2* #this, self::Extension2|genericMethod::T* t) → core::int* {
   core::print("Extension2.genericMethod<${self::Extension2|genericMethod::T*}>(${t}) on ${#this}");
   return #this.{self::Class2::field}.{core::num::+}(t).{core::num::+}(4) as{TypeError} core::int*;
 }
-static method Extension2|get#genericMethod(lowered final self::Class2* #this) → <T extends core::num* = core::num*>(T*) →* core::int*
-  return <T extends core::num* = core::num*>(T* t) → core::int* => self::Extension2|genericMethod<T*>(#this, t);
+static method Extension2|get#genericMethod(lowered final self::Class2* #this) → <T extends core::num*>(T*) →* core::int*
+  return <T extends core::num*>(T* t) → core::int* => self::Extension2|genericMethod<T*>(#this, t);
 static method Extension2|get#property(lowered final self::Class2* #this) → core::int* {
   core::print("Extension2.property get on ${#this}");
   return #this.{self::Class2::field}.{core::num::+}(5);
diff --git a/pkg/front_end/testcases/extensions/instance_access.dart.weak.outline.expect b/pkg/front_end/testcases/extensions/instance_access.dart.weak.outline.expect
index 36f5cf9..4e0c07a 100644
--- a/pkg/front_end/testcases/extensions/instance_access.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/extensions/instance_access.dart.weak.outline.expect
@@ -54,10 +54,10 @@
   ;
 static method Extension1|get#method(lowered final self::Class1* #this) → () →* core::int*
   return () → core::int* => self::Extension1|method(#this);
-static method Extension1|genericMethod<T extends core::num* = core::num*>(lowered final self::Class1* #this, self::Extension1|genericMethod::T* t) → core::int*
+static method Extension1|genericMethod<T extends core::num*>(lowered final self::Class1* #this, self::Extension1|genericMethod::T* t) → core::int*
   ;
-static method Extension1|get#genericMethod(lowered final self::Class1* #this) → <T extends core::num* = core::num*>(T*) →* core::int*
-  return <T extends core::num* = core::num*>(T* t) → core::int* => self::Extension1|genericMethod<T*>(#this, t);
+static method Extension1|get#genericMethod(lowered final self::Class1* #this) → <T extends core::num*>(T*) →* core::int*
+  return <T extends core::num*>(T* t) → core::int* => self::Extension1|genericMethod<T*>(#this, t);
 static method Extension1|get#property(lowered final self::Class1* #this) → core::int*
   ;
 static method Extension1|set#property(lowered final self::Class1* #this, core::int* value) → void
@@ -66,10 +66,10 @@
   ;
 static method Extension2|get#method(lowered final self::Class2* #this) → () →* core::int*
   return () → core::int* => self::Extension2|method(#this);
-static method Extension2|genericMethod<T extends core::num* = core::num*>(lowered final self::Class2* #this, self::Extension2|genericMethod::T* t) → core::int*
+static method Extension2|genericMethod<T extends core::num*>(lowered final self::Class2* #this, self::Extension2|genericMethod::T* t) → core::int*
   ;
-static method Extension2|get#genericMethod(lowered final self::Class2* #this) → <T extends core::num* = core::num*>(T*) →* core::int*
-  return <T extends core::num* = core::num*>(T* t) → core::int* => self::Extension2|genericMethod<T*>(#this, t);
+static method Extension2|get#genericMethod(lowered final self::Class2* #this) → <T extends core::num*>(T*) →* core::int*
+  return <T extends core::num*>(T* t) → core::int* => self::Extension2|genericMethod<T*>(#this, t);
 static method Extension2|get#property(lowered final self::Class2* #this) → core::int*
   ;
 static method Extension2|set#property(lowered final self::Class2* #this, core::int* value) → void
diff --git a/pkg/front_end/testcases/extensions/instance_access.dart.weak.transformed.expect b/pkg/front_end/testcases/extensions/instance_access.dart.weak.transformed.expect
index 9d2558b..c022d12 100644
--- a/pkg/front_end/testcases/extensions/instance_access.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/extensions/instance_access.dart.weak.transformed.expect
@@ -58,12 +58,12 @@
 }
 static method Extension1|get#method(lowered final self::Class1* #this) → () →* core::int*
   return () → core::int* => self::Extension1|method(#this);
-static method Extension1|genericMethod<T extends core::num* = core::num*>(lowered final self::Class1* #this, self::Extension1|genericMethod::T* t) → core::int* {
+static method Extension1|genericMethod<T extends core::num*>(lowered final self::Class1* #this, self::Extension1|genericMethod::T* t) → core::int* {
   core::print("Extension1.genericMethod<${self::Extension1|genericMethod::T*}>(${t}) on ${#this}");
   return #this.{self::Class1::field}.{core::num::+}(t) as{TypeError} core::int*;
 }
-static method Extension1|get#genericMethod(lowered final self::Class1* #this) → <T extends core::num* = core::num*>(T*) →* core::int*
-  return <T extends core::num* = core::num*>(T* t) → core::int* => self::Extension1|genericMethod<T*>(#this, t);
+static method Extension1|get#genericMethod(lowered final self::Class1* #this) → <T extends core::num*>(T*) →* core::int*
+  return <T extends core::num*>(T* t) → core::int* => self::Extension1|genericMethod<T*>(#this, t);
 static method Extension1|get#property(lowered final self::Class1* #this) → core::int* {
   core::print("Extension1.property get on ${#this}");
   return #this.{self::Class1::field};
@@ -79,12 +79,12 @@
 }
 static method Extension2|get#method(lowered final self::Class2* #this) → () →* core::int*
   return () → core::int* => self::Extension2|method(#this);
-static method Extension2|genericMethod<T extends core::num* = core::num*>(lowered final self::Class2* #this, self::Extension2|genericMethod::T* t) → core::int* {
+static method Extension2|genericMethod<T extends core::num*>(lowered final self::Class2* #this, self::Extension2|genericMethod::T* t) → core::int* {
   core::print("Extension2.genericMethod<${self::Extension2|genericMethod::T*}>(${t}) on ${#this}");
   return #this.{self::Class2::field}.{core::num::+}(t).{core::num::+}(4) as{TypeError} core::int*;
 }
-static method Extension2|get#genericMethod(lowered final self::Class2* #this) → <T extends core::num* = core::num*>(T*) →* core::int*
-  return <T extends core::num* = core::num*>(T* t) → core::int* => self::Extension2|genericMethod<T*>(#this, t);
+static method Extension2|get#genericMethod(lowered final self::Class2* #this) → <T extends core::num*>(T*) →* core::int*
+  return <T extends core::num*>(T* t) → core::int* => self::Extension2|genericMethod<T*>(#this, t);
 static method Extension2|get#property(lowered final self::Class2* #this) → core::int* {
   core::print("Extension2.property get on ${#this}");
   return #this.{self::Class2::field}.{core::num::+}(5);
diff --git a/pkg/front_end/testcases/extensions/instance_tearoff.dart.weak.expect b/pkg/front_end/testcases/extensions/instance_tearoff.dart.weak.expect
index 3e30930..7ff18f4 100644
--- a/pkg/front_end/testcases/extensions/instance_tearoff.dart.weak.expect
+++ b/pkg/front_end/testcases/extensions/instance_tearoff.dart.weak.expect
@@ -54,24 +54,24 @@
 }
 static method Extension1|get#method(lowered final self::Class1* #this) → () →* core::int*
   return () → core::int* => self::Extension1|method(#this);
-static method Extension1|genericMethod<T extends core::num* = core::num*>(lowered final self::Class1* #this, self::Extension1|genericMethod::T* t) → core::int* {
+static method Extension1|genericMethod<T extends core::num*>(lowered final self::Class1* #this, self::Extension1|genericMethod::T* t) → core::int* {
   core::print("Extension1.genericMethod<${self::Extension1|genericMethod::T*}>(${t}) on ${#this}");
   return #this.{self::Class1::field}.{core::num::+}(t) as{TypeError} core::int*;
 }
-static method Extension1|get#genericMethod(lowered final self::Class1* #this) → <T extends core::num* = core::num*>(T*) →* core::int*
-  return <T extends core::num* = core::num*>(T* t) → core::int* => self::Extension1|genericMethod<T*>(#this, t);
+static method Extension1|get#genericMethod(lowered final self::Class1* #this) → <T extends core::num*>(T*) →* core::int*
+  return <T extends core::num*>(T* t) → core::int* => self::Extension1|genericMethod<T*>(#this, t);
 static method Extension2|method(lowered final self::Class2* #this) → core::int* {
   core::print("Extension2.method on ${#this}");
   return #this.{self::Class2::field}.{core::num::+}(2);
 }
 static method Extension2|get#method(lowered final self::Class2* #this) → () →* core::int*
   return () → core::int* => self::Extension2|method(#this);
-static method Extension2|genericMethod<T extends core::num* = core::num*>(lowered final self::Class2* #this, self::Extension2|genericMethod::T* t) → core::int* {
+static method Extension2|genericMethod<T extends core::num*>(lowered final self::Class2* #this, self::Extension2|genericMethod::T* t) → core::int* {
   core::print("Extension2.genericMethod<${self::Extension2|genericMethod::T*}>(${t}) on ${#this}");
   return #this.{self::Class2::field}.{core::num::+}(t).{core::num::+}(3) as{TypeError} core::int*;
 }
-static method Extension2|get#genericMethod(lowered final self::Class2* #this) → <T extends core::num* = core::num*>(T*) →* core::int*
-  return <T extends core::num* = core::num*>(T* t) → core::int* => self::Extension2|genericMethod<T*>(#this, t);
+static method Extension2|get#genericMethod(lowered final self::Class2* #this) → <T extends core::num*>(T*) →* core::int*
+  return <T extends core::num*>(T* t) → core::int* => self::Extension2|genericMethod<T*>(#this, t);
 static method main() → dynamic {
   self::testExtension1();
   self::testExtension2();
@@ -87,10 +87,10 @@
   self::expect(1, tearOff1.call());
   c1 = new self::Class1::•(7.{core::int::unary-}());
   self::expect(1, tearOff1.call());
-  <T extends core::num* = core::num*>(T*) →* core::int* genericTearOff0 = self::Extension1|get#genericMethod(c0);
+  <T extends core::num*>(T*) →* core::int* genericTearOff0 = self::Extension1|get#genericMethod(c0);
   self::expect(38, genericTearOff0.call<core::int*>(42));
   self::expect(38, genericTearOff0.call<core::num*>(42));
-  <T extends core::num* = core::num*>(T*) →* core::int* genericTearOff1 = self::Extension1|get#genericMethod(c1);
+  <T extends core::num*>(T*) →* core::int* genericTearOff1 = self::Extension1|get#genericMethod(c1);
   self::expect(35, genericTearOff1.call<core::int*>(42));
   self::expect(35, genericTearOff1.call<core::num*>(42));
 }
@@ -105,10 +105,10 @@
   self::expect(3, tearOff1.call());
   c1 = new self::Class2::•(7.{core::int::unary-}());
   self::expect(3, tearOff1.call());
-  <T extends core::num* = core::num*>(T*) →* core::int* genericTearOff0 = self::Extension2|get#genericMethod(c0);
+  <T extends core::num*>(T*) →* core::int* genericTearOff0 = self::Extension2|get#genericMethod(c0);
   self::expect(41, genericTearOff0.call<core::int*>(42));
   self::expect(41, genericTearOff0.call<core::num*>(42));
-  <T extends core::num* = core::num*>(T*) →* core::int* genericTearOff1 = self::Extension2|get#genericMethod(c1);
+  <T extends core::num*>(T*) →* core::int* genericTearOff1 = self::Extension2|get#genericMethod(c1);
   self::expect(38, genericTearOff1.call<core::int*>(42));
   self::expect(38, genericTearOff1.call<core::num*>(42));
 }
diff --git a/pkg/front_end/testcases/extensions/instance_tearoff.dart.weak.outline.expect b/pkg/front_end/testcases/extensions/instance_tearoff.dart.weak.outline.expect
index 03756cc..8d3c1e7 100644
--- a/pkg/front_end/testcases/extensions/instance_tearoff.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/extensions/instance_tearoff.dart.weak.outline.expect
@@ -50,18 +50,18 @@
   ;
 static method Extension1|get#method(lowered final self::Class1* #this) → () →* core::int*
   return () → core::int* => self::Extension1|method(#this);
-static method Extension1|genericMethod<T extends core::num* = core::num*>(lowered final self::Class1* #this, self::Extension1|genericMethod::T* t) → core::int*
+static method Extension1|genericMethod<T extends core::num*>(lowered final self::Class1* #this, self::Extension1|genericMethod::T* t) → core::int*
   ;
-static method Extension1|get#genericMethod(lowered final self::Class1* #this) → <T extends core::num* = core::num*>(T*) →* core::int*
-  return <T extends core::num* = core::num*>(T* t) → core::int* => self::Extension1|genericMethod<T*>(#this, t);
+static method Extension1|get#genericMethod(lowered final self::Class1* #this) → <T extends core::num*>(T*) →* core::int*
+  return <T extends core::num*>(T* t) → core::int* => self::Extension1|genericMethod<T*>(#this, t);
 static method Extension2|method(lowered final self::Class2* #this) → core::int*
   ;
 static method Extension2|get#method(lowered final self::Class2* #this) → () →* core::int*
   return () → core::int* => self::Extension2|method(#this);
-static method Extension2|genericMethod<T extends core::num* = core::num*>(lowered final self::Class2* #this, self::Extension2|genericMethod::T* t) → core::int*
+static method Extension2|genericMethod<T extends core::num*>(lowered final self::Class2* #this, self::Extension2|genericMethod::T* t) → core::int*
   ;
-static method Extension2|get#genericMethod(lowered final self::Class2* #this) → <T extends core::num* = core::num*>(T*) →* core::int*
-  return <T extends core::num* = core::num*>(T* t) → core::int* => self::Extension2|genericMethod<T*>(#this, t);
+static method Extension2|get#genericMethod(lowered final self::Class2* #this) → <T extends core::num*>(T*) →* core::int*
+  return <T extends core::num*>(T* t) → core::int* => self::Extension2|genericMethod<T*>(#this, t);
 static method main() → dynamic
   ;
 static method testExtension1() → dynamic
diff --git a/pkg/front_end/testcases/extensions/instance_tearoff.dart.weak.transformed.expect b/pkg/front_end/testcases/extensions/instance_tearoff.dart.weak.transformed.expect
index 70b8f9f..1c79b12 100644
--- a/pkg/front_end/testcases/extensions/instance_tearoff.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/extensions/instance_tearoff.dart.weak.transformed.expect
@@ -54,24 +54,24 @@
 }
 static method Extension1|get#method(lowered final self::Class1* #this) → () →* core::int*
   return () → core::int* => self::Extension1|method(#this);
-static method Extension1|genericMethod<T extends core::num* = core::num*>(lowered final self::Class1* #this, self::Extension1|genericMethod::T* t) → core::int* {
+static method Extension1|genericMethod<T extends core::num*>(lowered final self::Class1* #this, self::Extension1|genericMethod::T* t) → core::int* {
   core::print("Extension1.genericMethod<${self::Extension1|genericMethod::T*}>(${t}) on ${#this}");
   return #this.{self::Class1::field}.{core::num::+}(t) as{TypeError} core::int*;
 }
-static method Extension1|get#genericMethod(lowered final self::Class1* #this) → <T extends core::num* = core::num*>(T*) →* core::int*
-  return <T extends core::num* = core::num*>(T* t) → core::int* => self::Extension1|genericMethod<T*>(#this, t);
+static method Extension1|get#genericMethod(lowered final self::Class1* #this) → <T extends core::num*>(T*) →* core::int*
+  return <T extends core::num*>(T* t) → core::int* => self::Extension1|genericMethod<T*>(#this, t);
 static method Extension2|method(lowered final self::Class2* #this) → core::int* {
   core::print("Extension2.method on ${#this}");
   return #this.{self::Class2::field}.{core::num::+}(2);
 }
 static method Extension2|get#method(lowered final self::Class2* #this) → () →* core::int*
   return () → core::int* => self::Extension2|method(#this);
-static method Extension2|genericMethod<T extends core::num* = core::num*>(lowered final self::Class2* #this, self::Extension2|genericMethod::T* t) → core::int* {
+static method Extension2|genericMethod<T extends core::num*>(lowered final self::Class2* #this, self::Extension2|genericMethod::T* t) → core::int* {
   core::print("Extension2.genericMethod<${self::Extension2|genericMethod::T*}>(${t}) on ${#this}");
   return #this.{self::Class2::field}.{core::num::+}(t).{core::num::+}(3) as{TypeError} core::int*;
 }
-static method Extension2|get#genericMethod(lowered final self::Class2* #this) → <T extends core::num* = core::num*>(T*) →* core::int*
-  return <T extends core::num* = core::num*>(T* t) → core::int* => self::Extension2|genericMethod<T*>(#this, t);
+static method Extension2|get#genericMethod(lowered final self::Class2* #this) → <T extends core::num*>(T*) →* core::int*
+  return <T extends core::num*>(T* t) → core::int* => self::Extension2|genericMethod<T*>(#this, t);
 static method main() → dynamic {
   self::testExtension1();
   self::testExtension2();
@@ -87,10 +87,10 @@
   self::expect(1, tearOff1.call());
   c1 = new self::Class1::•(7.{core::int::unary-}());
   self::expect(1, tearOff1.call());
-  <T extends core::num* = core::num*>(T*) →* core::int* genericTearOff0 = self::Extension1|get#genericMethod(c0);
+  <T extends core::num*>(T*) →* core::int* genericTearOff0 = self::Extension1|get#genericMethod(c0);
   self::expect(38, genericTearOff0.call<core::int*>(42));
   self::expect(38, genericTearOff0.call<core::num*>(42));
-  <T extends core::num* = core::num*>(T*) →* core::int* genericTearOff1 = self::Extension1|get#genericMethod(c1);
+  <T extends core::num*>(T*) →* core::int* genericTearOff1 = self::Extension1|get#genericMethod(c1);
   self::expect(35, genericTearOff1.call<core::int*>(42));
   self::expect(35, genericTearOff1.call<core::num*>(42));
 }
@@ -105,10 +105,10 @@
   self::expect(3, tearOff1.call());
   c1 = new self::Class2::•(7.{core::int::unary-}());
   self::expect(3, tearOff1.call());
-  <T extends core::num* = core::num*>(T*) →* core::int* genericTearOff0 = self::Extension2|get#genericMethod(c0);
+  <T extends core::num*>(T*) →* core::int* genericTearOff0 = self::Extension2|get#genericMethod(c0);
   self::expect(41, genericTearOff0.call<core::int*>(42));
   self::expect(41, genericTearOff0.call<core::num*>(42));
-  <T extends core::num* = core::num*>(T*) →* core::int* genericTearOff1 = self::Extension2|get#genericMethod(c1);
+  <T extends core::num*>(T*) →* core::int* genericTearOff1 = self::Extension2|get#genericMethod(c1);
   self::expect(38, genericTearOff1.call<core::int*>(42));
   self::expect(38, genericTearOff1.call<core::num*>(42));
 }
diff --git a/pkg/front_end/testcases/extensions/language_issue1182.dart.weak.expect b/pkg/front_end/testcases/extensions/language_issue1182.dart.weak.expect
index ada1a5c..b657553 100644
--- a/pkg/front_end/testcases/extensions/language_issue1182.dart.weak.expect
+++ b/pkg/front_end/testcases/extensions/language_issue1182.dart.weak.expect
@@ -9,7 +9,7 @@
 import self as self;
 import "dart:core" as core;
 
-class Foo<S extends core::num* = core::num*> extends core::Object {
+class Foo<S extends core::num*> extends core::Object {
   synthetic constructor •() → self::Foo<self::Foo::S*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/extensions/language_issue1182.dart.weak.outline.expect b/pkg/front_end/testcases/extensions/language_issue1182.dart.weak.outline.expect
index 44bd9dc..cf1db41 100644
--- a/pkg/front_end/testcases/extensions/language_issue1182.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/extensions/language_issue1182.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class Foo<S extends core::num* = core::num*> extends core::Object {
+class Foo<S extends core::num*> extends core::Object {
   synthetic constructor •() → self::Foo<self::Foo::S*>*
     ;
   method test1(generic-covariant-impl self::Foo::S* x) → void
diff --git a/pkg/front_end/testcases/extensions/language_issue1182.dart.weak.transformed.expect b/pkg/front_end/testcases/extensions/language_issue1182.dart.weak.transformed.expect
index ada1a5c..b657553 100644
--- a/pkg/front_end/testcases/extensions/language_issue1182.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/extensions/language_issue1182.dart.weak.transformed.expect
@@ -9,7 +9,7 @@
 import self as self;
 import "dart:core" as core;
 
-class Foo<S extends core::num* = core::num*> extends core::Object {
+class Foo<S extends core::num*> extends core::Object {
   synthetic constructor •() → self::Foo<self::Foo::S*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/extensions/on_function_type.dart.weak.expect b/pkg/front_end/testcases/extensions/on_function_type.dart.weak.expect
index 9c1f826..7fd4a5b 100644
--- a/pkg/front_end/testcases/extensions/on_function_type.dart.weak.expect
+++ b/pkg/front_end/testcases/extensions/on_function_type.dart.weak.expect
@@ -40,7 +40,7 @@
     return i;
   core::print(self::_extension#0|get#returnType<core::int*, core::int*>(local1));
   core::print(self::_extension#0|get#parameterType<core::int*, core::int*>(local1));
-  function local2<S extends self::Subclass* = self::Subclass*>(self::Subclass* a, S* b) → self::Subclass*
+  function local2<S extends self::Subclass*>(self::Subclass* a, S* b) → self::Subclass*
     return a;
   core::print(self::_extension#1|get#parameterType<self::Subclass*>(local2));
 }
diff --git a/pkg/front_end/testcases/extensions/on_function_type.dart.weak.transformed.expect b/pkg/front_end/testcases/extensions/on_function_type.dart.weak.transformed.expect
index 9c1f826..7fd4a5b 100644
--- a/pkg/front_end/testcases/extensions/on_function_type.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/extensions/on_function_type.dart.weak.transformed.expect
@@ -40,7 +40,7 @@
     return i;
   core::print(self::_extension#0|get#returnType<core::int*, core::int*>(local1));
   core::print(self::_extension#0|get#parameterType<core::int*, core::int*>(local1));
-  function local2<S extends self::Subclass* = self::Subclass*>(self::Subclass* a, S* b) → self::Subclass*
+  function local2<S extends self::Subclass*>(self::Subclass* a, S* b) → self::Subclass*
     return a;
   core::print(self::_extension#1|get#parameterType<self::Subclass*>(local2));
 }
diff --git a/pkg/front_end/testcases/extensions/on_type_inference.dart.weak.expect b/pkg/front_end/testcases/extensions/on_type_inference.dart.weak.expect
index 75adac2..a5fc214 100644
--- a/pkg/front_end/testcases/extensions/on_type_inference.dart.weak.expect
+++ b/pkg/front_end/testcases/extensions/on_type_inference.dart.weak.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-extension BestCom<T extends core::num* = core::num*> on core::Iterable<T*>* {
+extension BestCom<T extends core::num*> on core::Iterable<T*>* {
   method best = self::BestCom|best;
   tearoff best = self::BestCom|get#best;
 }
@@ -14,9 +14,9 @@
   method best = self::BestSpec|best;
   tearoff best = self::BestSpec|get#best;
 }
-static method BestCom|best<T extends core::num* = core::num*>(lowered final core::Iterable<self::BestCom|best::T*>* #this) → self::BestCom|best::T*
+static method BestCom|best<T extends core::num*>(lowered final core::Iterable<self::BestCom|best::T*>* #this) → self::BestCom|best::T*
   return null;
-static method BestCom|get#best<T extends core::num* = core::num*>(lowered final core::Iterable<self::BestCom|get#best::T*>* #this) → () →* self::BestCom|get#best::T*
+static method BestCom|get#best<T extends core::num*>(lowered final core::Iterable<self::BestCom|get#best::T*>* #this) → () →* self::BestCom|get#best::T*
   return () → self::BestCom|get#best::T* => self::BestCom|best<self::BestCom|get#best::T*>(#this);
 static method BestList|best<T extends core::Object* = dynamic>(lowered final core::List<self::BestList|best::T*>* #this) → self::BestList|best::T*
   return null;
diff --git a/pkg/front_end/testcases/extensions/on_type_inference.dart.weak.outline.expect b/pkg/front_end/testcases/extensions/on_type_inference.dart.weak.outline.expect
index f2746bb..e1ea935 100644
--- a/pkg/front_end/testcases/extensions/on_type_inference.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/extensions/on_type_inference.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-extension BestCom<T extends core::num* = core::num*> on core::Iterable<T*>* {
+extension BestCom<T extends core::num*> on core::Iterable<T*>* {
   method best = self::BestCom|best;
   tearoff best = self::BestCom|get#best;
 }
@@ -14,9 +14,9 @@
   method best = self::BestSpec|best;
   tearoff best = self::BestSpec|get#best;
 }
-static method BestCom|best<T extends core::num* = core::num*>(lowered final core::Iterable<self::BestCom|best::T*>* #this) → self::BestCom|best::T*
+static method BestCom|best<T extends core::num*>(lowered final core::Iterable<self::BestCom|best::T*>* #this) → self::BestCom|best::T*
   ;
-static method BestCom|get#best<T extends core::num* = core::num*>(lowered final core::Iterable<self::BestCom|get#best::T*>* #this) → () →* self::BestCom|get#best::T*
+static method BestCom|get#best<T extends core::num*>(lowered final core::Iterable<self::BestCom|get#best::T*>* #this) → () →* self::BestCom|get#best::T*
   return () → self::BestCom|get#best::T* => self::BestCom|best<self::BestCom|get#best::T*>(#this);
 static method BestList|best<T extends core::Object* = dynamic>(lowered final core::List<self::BestList|best::T*>* #this) → self::BestList|best::T*
   ;
diff --git a/pkg/front_end/testcases/extensions/on_type_inference.dart.weak.transformed.expect b/pkg/front_end/testcases/extensions/on_type_inference.dart.weak.transformed.expect
index 75adac2..a5fc214 100644
--- a/pkg/front_end/testcases/extensions/on_type_inference.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/extensions/on_type_inference.dart.weak.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-extension BestCom<T extends core::num* = core::num*> on core::Iterable<T*>* {
+extension BestCom<T extends core::num*> on core::Iterable<T*>* {
   method best = self::BestCom|best;
   tearoff best = self::BestCom|get#best;
 }
@@ -14,9 +14,9 @@
   method best = self::BestSpec|best;
   tearoff best = self::BestSpec|get#best;
 }
-static method BestCom|best<T extends core::num* = core::num*>(lowered final core::Iterable<self::BestCom|best::T*>* #this) → self::BestCom|best::T*
+static method BestCom|best<T extends core::num*>(lowered final core::Iterable<self::BestCom|best::T*>* #this) → self::BestCom|best::T*
   return null;
-static method BestCom|get#best<T extends core::num* = core::num*>(lowered final core::Iterable<self::BestCom|get#best::T*>* #this) → () →* self::BestCom|get#best::T*
+static method BestCom|get#best<T extends core::num*>(lowered final core::Iterable<self::BestCom|get#best::T*>* #this) → () →* self::BestCom|get#best::T*
   return () → self::BestCom|get#best::T* => self::BestCom|best<self::BestCom|get#best::T*>(#this);
 static method BestList|best<T extends core::Object* = dynamic>(lowered final core::List<self::BestList|best::T*>* #this) → self::BestList|best::T*
   return null;
diff --git a/pkg/front_end/testcases/extensions/on_type_variable_inference.dart.weak.expect b/pkg/front_end/testcases/extensions/on_type_variable_inference.dart.weak.expect
index 21907d2..4fa3d96 100644
--- a/pkg/front_end/testcases/extensions/on_type_variable_inference.dart.weak.expect
+++ b/pkg/front_end/testcases/extensions/on_type_variable_inference.dart.weak.expect
@@ -81,19 +81,19 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-extension Extension<T extends self::Struct* = self::Struct*> on T* {
+extension Extension<T extends self::Struct*> on T* {
   method method = self::Extension|method;
   tearoff method = self::Extension|get#method;
   get property = self::Extension|get#property;
   set property = self::Extension|set#property;
 }
-static method Extension|method<T extends self::Struct* = self::Struct*>(lowered final self::Extension|method::T* #this) → self::Extension|method::T*
+static method Extension|method<T extends self::Struct*>(lowered final self::Extension|method::T* #this) → self::Extension|method::T*
   return #this;
-static method Extension|get#method<T extends self::Struct* = self::Struct*>(lowered final self::Extension|get#method::T* #this) → () →* self::Extension|get#method::T*
+static method Extension|get#method<T extends self::Struct*>(lowered final self::Extension|get#method::T* #this) → () →* self::Extension|get#method::T*
   return () → self::Extension|get#method::T* => self::Extension|method<self::Extension|get#method::T*>(#this);
-static method Extension|get#property<T extends self::Struct* = self::Struct*>(lowered final self::Extension|get#property::T* #this) → self::Extension|get#property::T*
+static method Extension|get#property<T extends self::Struct*>(lowered final self::Extension|get#property::T* #this) → self::Extension|get#property::T*
   return #this;
-static method Extension|set#property<T extends self::Struct* = self::Struct*>(lowered final self::Extension|set#property::T* #this, self::Extension|set#property::T* value) → void {}
+static method Extension|set#property<T extends self::Struct*>(lowered final self::Extension|set#property::T* #this, self::Extension|set#property::T* value) → void {}
 static method main() → dynamic {
   self::Struct* struct;
   self::StructA* structA;
diff --git a/pkg/front_end/testcases/extensions/on_type_variable_inference.dart.weak.outline.expect b/pkg/front_end/testcases/extensions/on_type_variable_inference.dart.weak.outline.expect
index 3dd1c35..4503bad 100644
--- a/pkg/front_end/testcases/extensions/on_type_variable_inference.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/extensions/on_type_variable_inference.dart.weak.outline.expect
@@ -38,19 +38,19 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-extension Extension<T extends self::Struct* = self::Struct*> on T* {
+extension Extension<T extends self::Struct*> on T* {
   method method = self::Extension|method;
   tearoff method = self::Extension|get#method;
   get property = self::Extension|get#property;
   set property = self::Extension|set#property;
 }
-static method Extension|method<T extends self::Struct* = self::Struct*>(lowered final self::Extension|method::T* #this) → self::Extension|method::T*
+static method Extension|method<T extends self::Struct*>(lowered final self::Extension|method::T* #this) → self::Extension|method::T*
   ;
-static method Extension|get#method<T extends self::Struct* = self::Struct*>(lowered final self::Extension|get#method::T* #this) → () →* self::Extension|get#method::T*
+static method Extension|get#method<T extends self::Struct*>(lowered final self::Extension|get#method::T* #this) → () →* self::Extension|get#method::T*
   return () → self::Extension|get#method::T* => self::Extension|method<self::Extension|get#method::T*>(#this);
-static method Extension|get#property<T extends self::Struct* = self::Struct*>(lowered final self::Extension|get#property::T* #this) → self::Extension|get#property::T*
+static method Extension|get#property<T extends self::Struct*>(lowered final self::Extension|get#property::T* #this) → self::Extension|get#property::T*
   ;
-static method Extension|set#property<T extends self::Struct* = self::Struct*>(lowered final self::Extension|set#property::T* #this, self::Extension|set#property::T* value) → void
+static method Extension|set#property<T extends self::Struct*>(lowered final self::Extension|set#property::T* #this, self::Extension|set#property::T* value) → void
   ;
 static method main() → dynamic
   ;
diff --git a/pkg/front_end/testcases/extensions/on_type_variable_inference.dart.weak.transformed.expect b/pkg/front_end/testcases/extensions/on_type_variable_inference.dart.weak.transformed.expect
index 21907d2..4fa3d96 100644
--- a/pkg/front_end/testcases/extensions/on_type_variable_inference.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/extensions/on_type_variable_inference.dart.weak.transformed.expect
@@ -81,19 +81,19 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-extension Extension<T extends self::Struct* = self::Struct*> on T* {
+extension Extension<T extends self::Struct*> on T* {
   method method = self::Extension|method;
   tearoff method = self::Extension|get#method;
   get property = self::Extension|get#property;
   set property = self::Extension|set#property;
 }
-static method Extension|method<T extends self::Struct* = self::Struct*>(lowered final self::Extension|method::T* #this) → self::Extension|method::T*
+static method Extension|method<T extends self::Struct*>(lowered final self::Extension|method::T* #this) → self::Extension|method::T*
   return #this;
-static method Extension|get#method<T extends self::Struct* = self::Struct*>(lowered final self::Extension|get#method::T* #this) → () →* self::Extension|get#method::T*
+static method Extension|get#method<T extends self::Struct*>(lowered final self::Extension|get#method::T* #this) → () →* self::Extension|get#method::T*
   return () → self::Extension|get#method::T* => self::Extension|method<self::Extension|get#method::T*>(#this);
-static method Extension|get#property<T extends self::Struct* = self::Struct*>(lowered final self::Extension|get#property::T* #this) → self::Extension|get#property::T*
+static method Extension|get#property<T extends self::Struct*>(lowered final self::Extension|get#property::T* #this) → self::Extension|get#property::T*
   return #this;
-static method Extension|set#property<T extends self::Struct* = self::Struct*>(lowered final self::Extension|set#property::T* #this, self::Extension|set#property::T* value) → void {}
+static method Extension|set#property<T extends self::Struct*>(lowered final self::Extension|set#property::T* #this, self::Extension|set#property::T* value) → void {}
 static method main() → dynamic {
   self::Struct* struct;
   self::StructA* structA;
diff --git a/pkg/front_end/testcases/extensions/type_variable_bound.dart.weak.expect b/pkg/front_end/testcases/extensions/type_variable_bound.dart.weak.expect
index a20912a..5b11e7e 100644
--- a/pkg/front_end/testcases/extensions/type_variable_bound.dart.weak.expect
+++ b/pkg/front_end/testcases/extensions/type_variable_bound.dart.weak.expect
@@ -26,7 +26,7 @@
   method method1 = self::Extension|method1;
   tearoff method1 = self::Extension|get#method1;
 }
-extension BoundExtension<T extends self::Class* = self::Class*> on T* {
+extension BoundExtension<T extends self::Class*> on T* {
   method method2 = self::BoundExtension|method2;
   tearoff method2 = self::BoundExtension|get#method2;
 }
@@ -34,9 +34,9 @@
   return #this;
 static method Extension|get#method1<T extends core::Object* = dynamic>(lowered final self::Extension|get#method1::T* #this) → () →* self::Extension|get#method1::T*
   return () → self::Extension|get#method1::T* => self::Extension|method1<self::Extension|get#method1::T*>(#this);
-static method BoundExtension|method2<T extends self::Class* = self::Class*>(lowered final self::BoundExtension|method2::T* #this) → self::BoundExtension|method2::T*
+static method BoundExtension|method2<T extends self::Class*>(lowered final self::BoundExtension|method2::T* #this) → self::BoundExtension|method2::T*
   return #this;
-static method BoundExtension|get#method2<T extends self::Class* = self::Class*>(lowered final self::BoundExtension|get#method2::T* #this) → () →* self::BoundExtension|get#method2::T*
+static method BoundExtension|get#method2<T extends self::Class*>(lowered final self::BoundExtension|get#method2::T* #this) → () →* self::BoundExtension|get#method2::T*
   return () → self::BoundExtension|get#method2::T* => self::BoundExtension|method2<self::BoundExtension|get#method2::T*>(#this);
 static method test1<T extends core::Object* = dynamic>(self::test1::T* t1) → self::Class* {
   if(t1 is self::SubClass*) {
@@ -44,7 +44,7 @@
   }
   return new self::Class::•();
 }
-static method test2<T extends self::Class* = self::Class*>(self::test2::T* t2) → dynamic {
+static method test2<T extends self::Class*>(self::test2::T* t2) → dynamic {
   if(self::test2::T*.{core::Type::==}(#C1)) {
     self::SubClass* subClass = self::BoundExtension|method2<self::Class*>(t2) as{TypeError} self::SubClass*;
   }
diff --git a/pkg/front_end/testcases/extensions/type_variable_bound.dart.weak.outline.expect b/pkg/front_end/testcases/extensions/type_variable_bound.dart.weak.outline.expect
index 6efbb7d..e51a6e0 100644
--- a/pkg/front_end/testcases/extensions/type_variable_bound.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/extensions/type_variable_bound.dart.weak.outline.expect
@@ -24,7 +24,7 @@
   method method1 = self::Extension|method1;
   tearoff method1 = self::Extension|get#method1;
 }
-extension BoundExtension<T extends self::Class* = self::Class*> on T* {
+extension BoundExtension<T extends self::Class*> on T* {
   method method2 = self::BoundExtension|method2;
   tearoff method2 = self::BoundExtension|get#method2;
 }
@@ -32,13 +32,13 @@
   ;
 static method Extension|get#method1<T extends core::Object* = dynamic>(lowered final self::Extension|get#method1::T* #this) → () →* self::Extension|get#method1::T*
   return () → self::Extension|get#method1::T* => self::Extension|method1<self::Extension|get#method1::T*>(#this);
-static method BoundExtension|method2<T extends self::Class* = self::Class*>(lowered final self::BoundExtension|method2::T* #this) → self::BoundExtension|method2::T*
+static method BoundExtension|method2<T extends self::Class*>(lowered final self::BoundExtension|method2::T* #this) → self::BoundExtension|method2::T*
   ;
-static method BoundExtension|get#method2<T extends self::Class* = self::Class*>(lowered final self::BoundExtension|get#method2::T* #this) → () →* self::BoundExtension|get#method2::T*
+static method BoundExtension|get#method2<T extends self::Class*>(lowered final self::BoundExtension|get#method2::T* #this) → () →* self::BoundExtension|get#method2::T*
   return () → self::BoundExtension|get#method2::T* => self::BoundExtension|method2<self::BoundExtension|get#method2::T*>(#this);
 static method test1<T extends core::Object* = dynamic>(self::test1::T* t1) → self::Class*
   ;
-static method test2<T extends self::Class* = self::Class*>(self::test2::T* t2) → dynamic
+static method test2<T extends self::Class*>(self::test2::T* t2) → dynamic
   ;
 static method test3<T extends core::Object* = dynamic>(self::test3::T* t3) → dynamic
   ;
diff --git a/pkg/front_end/testcases/extensions/type_variable_bound.dart.weak.transformed.expect b/pkg/front_end/testcases/extensions/type_variable_bound.dart.weak.transformed.expect
index a20912a..5b11e7e 100644
--- a/pkg/front_end/testcases/extensions/type_variable_bound.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/extensions/type_variable_bound.dart.weak.transformed.expect
@@ -26,7 +26,7 @@
   method method1 = self::Extension|method1;
   tearoff method1 = self::Extension|get#method1;
 }
-extension BoundExtension<T extends self::Class* = self::Class*> on T* {
+extension BoundExtension<T extends self::Class*> on T* {
   method method2 = self::BoundExtension|method2;
   tearoff method2 = self::BoundExtension|get#method2;
 }
@@ -34,9 +34,9 @@
   return #this;
 static method Extension|get#method1<T extends core::Object* = dynamic>(lowered final self::Extension|get#method1::T* #this) → () →* self::Extension|get#method1::T*
   return () → self::Extension|get#method1::T* => self::Extension|method1<self::Extension|get#method1::T*>(#this);
-static method BoundExtension|method2<T extends self::Class* = self::Class*>(lowered final self::BoundExtension|method2::T* #this) → self::BoundExtension|method2::T*
+static method BoundExtension|method2<T extends self::Class*>(lowered final self::BoundExtension|method2::T* #this) → self::BoundExtension|method2::T*
   return #this;
-static method BoundExtension|get#method2<T extends self::Class* = self::Class*>(lowered final self::BoundExtension|get#method2::T* #this) → () →* self::BoundExtension|get#method2::T*
+static method BoundExtension|get#method2<T extends self::Class*>(lowered final self::BoundExtension|get#method2::T* #this) → () →* self::BoundExtension|get#method2::T*
   return () → self::BoundExtension|get#method2::T* => self::BoundExtension|method2<self::BoundExtension|get#method2::T*>(#this);
 static method test1<T extends core::Object* = dynamic>(self::test1::T* t1) → self::Class* {
   if(t1 is self::SubClass*) {
@@ -44,7 +44,7 @@
   }
   return new self::Class::•();
 }
-static method test2<T extends self::Class* = self::Class*>(self::test2::T* t2) → dynamic {
+static method test2<T extends self::Class*>(self::test2::T* t2) → dynamic {
   if(self::test2::T*.{core::Type::==}(#C1)) {
     self::SubClass* subClass = self::BoundExtension|method2<self::Class*>(t2) as{TypeError} self::SubClass*;
   }
diff --git a/pkg/front_end/testcases/extensions/unnamed_extensions.dart.weak.expect b/pkg/front_end/testcases/extensions/unnamed_extensions.dart.weak.expect
index 1786045..932e48a 100644
--- a/pkg/front_end/testcases/extensions/unnamed_extensions.dart.weak.expect
+++ b/pkg/front_end/testcases/extensions/unnamed_extensions.dart.weak.expect
@@ -58,12 +58,12 @@
 }
 static method _extension#0|get#method(lowered final self::Class1* #this) → () →* core::int*
   return () → core::int* => self::_extension#0|method(#this);
-static method _extension#0|genericMethod<T extends core::num* = core::num*>(lowered final self::Class1* #this, self::_extension#0|genericMethod::T* t) → core::int* {
+static method _extension#0|genericMethod<T extends core::num*>(lowered final self::Class1* #this, self::_extension#0|genericMethod::T* t) → core::int* {
   core::print("Extension1.genericMethod<${self::_extension#0|genericMethod::T*}>(${t}) on ${#this}");
   return #this.{self::Class1::field}.{core::num::+}(t) as{TypeError} core::int*;
 }
-static method _extension#0|get#genericMethod(lowered final self::Class1* #this) → <T extends core::num* = core::num*>(T*) →* core::int*
-  return <T extends core::num* = core::num*>(T* t) → core::int* => self::_extension#0|genericMethod<T*>(#this, t);
+static method _extension#0|get#genericMethod(lowered final self::Class1* #this) → <T extends core::num*>(T*) →* core::int*
+  return <T extends core::num*>(T* t) → core::int* => self::_extension#0|genericMethod<T*>(#this, t);
 static method _extension#0|get#property(lowered final self::Class1* #this) → core::int* {
   core::print("Extension1.property get on ${#this}");
   return #this.{self::Class1::field};
@@ -79,12 +79,12 @@
 }
 static method _extension#1|get#method(lowered final self::Class2* #this) → () →* core::int*
   return () → core::int* => self::_extension#1|method(#this);
-static method _extension#1|genericMethod<T extends core::num* = core::num*>(lowered final self::Class2* #this, self::_extension#1|genericMethod::T* t) → core::int* {
+static method _extension#1|genericMethod<T extends core::num*>(lowered final self::Class2* #this, self::_extension#1|genericMethod::T* t) → core::int* {
   core::print("Extension2.genericMethod<${self::_extension#1|genericMethod::T*}>(${t}) on ${#this}");
   return #this.{self::Class2::field}.{core::num::+}(t).{core::num::+}(4) as{TypeError} core::int*;
 }
-static method _extension#1|get#genericMethod(lowered final self::Class2* #this) → <T extends core::num* = core::num*>(T*) →* core::int*
-  return <T extends core::num* = core::num*>(T* t) → core::int* => self::_extension#1|genericMethod<T*>(#this, t);
+static method _extension#1|get#genericMethod(lowered final self::Class2* #this) → <T extends core::num*>(T*) →* core::int*
+  return <T extends core::num*>(T* t) → core::int* => self::_extension#1|genericMethod<T*>(#this, t);
 static method _extension#1|get#property(lowered final self::Class2* #this) → core::int* {
   core::print("Extension2.property get on ${#this}");
   return #this.{self::Class2::field}.{core::num::+}(5);
diff --git a/pkg/front_end/testcases/extensions/unnamed_extensions.dart.weak.outline.expect b/pkg/front_end/testcases/extensions/unnamed_extensions.dart.weak.outline.expect
index bca6081..7880975 100644
--- a/pkg/front_end/testcases/extensions/unnamed_extensions.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/extensions/unnamed_extensions.dart.weak.outline.expect
@@ -54,10 +54,10 @@
   ;
 static method _extension#0|get#method(lowered final self::Class1* #this) → () →* core::int*
   return () → core::int* => self::_extension#0|method(#this);
-static method _extension#0|genericMethod<T extends core::num* = core::num*>(lowered final self::Class1* #this, self::_extension#0|genericMethod::T* t) → core::int*
+static method _extension#0|genericMethod<T extends core::num*>(lowered final self::Class1* #this, self::_extension#0|genericMethod::T* t) → core::int*
   ;
-static method _extension#0|get#genericMethod(lowered final self::Class1* #this) → <T extends core::num* = core::num*>(T*) →* core::int*
-  return <T extends core::num* = core::num*>(T* t) → core::int* => self::_extension#0|genericMethod<T*>(#this, t);
+static method _extension#0|get#genericMethod(lowered final self::Class1* #this) → <T extends core::num*>(T*) →* core::int*
+  return <T extends core::num*>(T* t) → core::int* => self::_extension#0|genericMethod<T*>(#this, t);
 static method _extension#0|get#property(lowered final self::Class1* #this) → core::int*
   ;
 static method _extension#0|set#property(lowered final self::Class1* #this, core::int* value) → void
@@ -66,10 +66,10 @@
   ;
 static method _extension#1|get#method(lowered final self::Class2* #this) → () →* core::int*
   return () → core::int* => self::_extension#1|method(#this);
-static method _extension#1|genericMethod<T extends core::num* = core::num*>(lowered final self::Class2* #this, self::_extension#1|genericMethod::T* t) → core::int*
+static method _extension#1|genericMethod<T extends core::num*>(lowered final self::Class2* #this, self::_extension#1|genericMethod::T* t) → core::int*
   ;
-static method _extension#1|get#genericMethod(lowered final self::Class2* #this) → <T extends core::num* = core::num*>(T*) →* core::int*
-  return <T extends core::num* = core::num*>(T* t) → core::int* => self::_extension#1|genericMethod<T*>(#this, t);
+static method _extension#1|get#genericMethod(lowered final self::Class2* #this) → <T extends core::num*>(T*) →* core::int*
+  return <T extends core::num*>(T* t) → core::int* => self::_extension#1|genericMethod<T*>(#this, t);
 static method _extension#1|get#property(lowered final self::Class2* #this) → core::int*
   ;
 static method _extension#1|set#property(lowered final self::Class2* #this, core::int* value) → void
diff --git a/pkg/front_end/testcases/extensions/unnamed_extensions.dart.weak.transformed.expect b/pkg/front_end/testcases/extensions/unnamed_extensions.dart.weak.transformed.expect
index 4e7371c..bfc173d 100644
--- a/pkg/front_end/testcases/extensions/unnamed_extensions.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/extensions/unnamed_extensions.dart.weak.transformed.expect
@@ -58,12 +58,12 @@
 }
 static method _extension#0|get#method(lowered final self::Class1* #this) → () →* core::int*
   return () → core::int* => self::_extension#0|method(#this);
-static method _extension#0|genericMethod<T extends core::num* = core::num*>(lowered final self::Class1* #this, self::_extension#0|genericMethod::T* t) → core::int* {
+static method _extension#0|genericMethod<T extends core::num*>(lowered final self::Class1* #this, self::_extension#0|genericMethod::T* t) → core::int* {
   core::print("Extension1.genericMethod<${self::_extension#0|genericMethod::T*}>(${t}) on ${#this}");
   return #this.{self::Class1::field}.{core::num::+}(t) as{TypeError} core::int*;
 }
-static method _extension#0|get#genericMethod(lowered final self::Class1* #this) → <T extends core::num* = core::num*>(T*) →* core::int*
-  return <T extends core::num* = core::num*>(T* t) → core::int* => self::_extension#0|genericMethod<T*>(#this, t);
+static method _extension#0|get#genericMethod(lowered final self::Class1* #this) → <T extends core::num*>(T*) →* core::int*
+  return <T extends core::num*>(T* t) → core::int* => self::_extension#0|genericMethod<T*>(#this, t);
 static method _extension#0|get#property(lowered final self::Class1* #this) → core::int* {
   core::print("Extension1.property get on ${#this}");
   return #this.{self::Class1::field};
@@ -79,12 +79,12 @@
 }
 static method _extension#1|get#method(lowered final self::Class2* #this) → () →* core::int*
   return () → core::int* => self::_extension#1|method(#this);
-static method _extension#1|genericMethod<T extends core::num* = core::num*>(lowered final self::Class2* #this, self::_extension#1|genericMethod::T* t) → core::int* {
+static method _extension#1|genericMethod<T extends core::num*>(lowered final self::Class2* #this, self::_extension#1|genericMethod::T* t) → core::int* {
   core::print("Extension2.genericMethod<${self::_extension#1|genericMethod::T*}>(${t}) on ${#this}");
   return #this.{self::Class2::field}.{core::num::+}(t).{core::num::+}(4) as{TypeError} core::int*;
 }
-static method _extension#1|get#genericMethod(lowered final self::Class2* #this) → <T extends core::num* = core::num*>(T*) →* core::int*
-  return <T extends core::num* = core::num*>(T* t) → core::int* => self::_extension#1|genericMethod<T*>(#this, t);
+static method _extension#1|get#genericMethod(lowered final self::Class2* #this) → <T extends core::num*>(T*) →* core::int*
+  return <T extends core::num*>(T* t) → core::int* => self::_extension#1|genericMethod<T*>(#this, t);
 static method _extension#1|get#property(lowered final self::Class2* #this) → core::int* {
   core::print("Extension2.property get on ${#this}");
   return #this.{self::Class2::field}.{core::num::+}(5);
diff --git a/pkg/front_end/testcases/general/bounds_check_depends_on_inference.dart.weak.expect b/pkg/front_end/testcases/general/bounds_check_depends_on_inference.dart.weak.expect
index d64170d..cd1a183 100644
--- a/pkg/front_end/testcases/general/bounds_check_depends_on_inference.dart.weak.expect
+++ b/pkg/front_end/testcases/general/bounds_check_depends_on_inference.dart.weak.expect
@@ -6,7 +6,7 @@
   synthetic constructor •() → self::A<self::A::X*>*
     : super core::Object::•()
     ;
-  method bar<generic-covariant-impl Y extends self::A::X* = self::A::X*>() → dynamic
+  method bar<generic-covariant-impl Y extends self::A::X*>() → dynamic
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -23,7 +23,7 @@
   synthetic constructor •() → self::B*
     : super core::Object::•()
     ;
-  static method foo<Y extends core::Object* = core::Object*>() → self::A<self::B::foo::Y*>*
+  static method foo<Y extends core::Object*>() → self::A<self::B::foo::Y*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
diff --git a/pkg/front_end/testcases/general/bounds_check_depends_on_inference.dart.weak.outline.expect b/pkg/front_end/testcases/general/bounds_check_depends_on_inference.dart.weak.outline.expect
index b5f4961..0828ddb 100644
--- a/pkg/front_end/testcases/general/bounds_check_depends_on_inference.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/bounds_check_depends_on_inference.dart.weak.outline.expect
@@ -5,7 +5,7 @@
 class A<X extends core::Object* = dynamic> extends core::Object {
   synthetic constructor •() → self::A<self::A::X*>*
     ;
-  method bar<generic-covariant-impl Y extends self::A::X* = self::A::X*>() → dynamic
+  method bar<generic-covariant-impl Y extends self::A::X*>() → dynamic
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -21,7 +21,7 @@
 class B extends core::Object {
   synthetic constructor •() → self::B*
     ;
-  static method foo<Y extends core::Object* = core::Object*>() → self::A<self::B::foo::Y*>*
+  static method foo<Y extends core::Object*>() → self::A<self::B::foo::Y*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
diff --git a/pkg/front_end/testcases/general/bounds_check_depends_on_inference.dart.weak.transformed.expect b/pkg/front_end/testcases/general/bounds_check_depends_on_inference.dart.weak.transformed.expect
index d64170d..cd1a183 100644
--- a/pkg/front_end/testcases/general/bounds_check_depends_on_inference.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/bounds_check_depends_on_inference.dart.weak.transformed.expect
@@ -6,7 +6,7 @@
   synthetic constructor •() → self::A<self::A::X*>*
     : super core::Object::•()
     ;
-  method bar<generic-covariant-impl Y extends self::A::X* = self::A::X*>() → dynamic
+  method bar<generic-covariant-impl Y extends self::A::X*>() → dynamic
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -23,7 +23,7 @@
   synthetic constructor •() → self::B*
     : super core::Object::•()
     ;
-  static method foo<Y extends core::Object* = core::Object*>() → self::A<self::B::foo::Y*>*
+  static method foo<Y extends core::Object*>() → self::A<self::B::foo::Y*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
diff --git a/pkg/front_end/testcases/general/bounds_check_in_typedef.dart.weak.expect b/pkg/front_end/testcases/general/bounds_check_in_typedef.dart.weak.expect
index 1bf550a..01f1570 100644
--- a/pkg/front_end/testcases/general/bounds_check_in_typedef.dart.weak.expect
+++ b/pkg/front_end/testcases/general/bounds_check_in_typedef.dart.weak.expect
@@ -23,7 +23,7 @@
 
 typedef F = <Y extends core::num* = dynamic>() →* <Z extends self::A<Y*>* = dynamic>() →* dynamic;
 typedef G = <Y extends core::num* = dynamic>(<Z extends self::A<Y*>* = dynamic>() →* dynamic) →* void;
-class A<X extends core::String* = core::String*> extends core::Object {
+class A<X extends core::String*> extends core::Object {
   synthetic constructor •() → self::A<self::A::X*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/general/bounds_check_in_typedef.dart.weak.outline.expect b/pkg/front_end/testcases/general/bounds_check_in_typedef.dart.weak.outline.expect
index cdad149..ffcf750 100644
--- a/pkg/front_end/testcases/general/bounds_check_in_typedef.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/bounds_check_in_typedef.dart.weak.outline.expect
@@ -23,7 +23,7 @@
 
 typedef F = <Y extends core::num* = dynamic>() →* <Z extends self::A<Y*>* = dynamic>() →* dynamic;
 typedef G = <Y extends core::num* = dynamic>(<Z extends self::A<Y*>* = dynamic>() →* dynamic) →* void;
-class A<X extends core::String* = core::String*> extends core::Object {
+class A<X extends core::String*> extends core::Object {
   synthetic constructor •() → self::A<self::A::X*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/general/bounds_check_in_typedef.dart.weak.transformed.expect b/pkg/front_end/testcases/general/bounds_check_in_typedef.dart.weak.transformed.expect
index 1bf550a..01f1570 100644
--- a/pkg/front_end/testcases/general/bounds_check_in_typedef.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/bounds_check_in_typedef.dart.weak.transformed.expect
@@ -23,7 +23,7 @@
 
 typedef F = <Y extends core::num* = dynamic>() →* <Z extends self::A<Y*>* = dynamic>() →* dynamic;
 typedef G = <Y extends core::num* = dynamic>(<Z extends self::A<Y*>* = dynamic>() →* dynamic) →* void;
-class A<X extends core::String* = core::String*> extends core::Object {
+class A<X extends core::String*> extends core::Object {
   synthetic constructor •() → self::A<self::A::X*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/general/bug35470.dart.weak.expect b/pkg/front_end/testcases/general/bug35470.dart.weak.expect
index 4bb1bd3..42009f8 100644
--- a/pkg/front_end/testcases/general/bug35470.dart.weak.expect
+++ b/pkg/front_end/testcases/general/bug35470.dart.weak.expect
@@ -6,7 +6,7 @@
   synthetic constructor •() → self::A<self::A::X*>*
     : super core::Object::•()
     ;
-  method foo<generic-covariant-impl Y extends self::A::X* = self::A::X*>() → dynamic {}
+  method foo<generic-covariant-impl Y extends self::A::X*>() → dynamic {}
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
diff --git a/pkg/front_end/testcases/general/bug35470.dart.weak.outline.expect b/pkg/front_end/testcases/general/bug35470.dart.weak.outline.expect
index bc8adee..bfe47d7 100644
--- a/pkg/front_end/testcases/general/bug35470.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/bug35470.dart.weak.outline.expect
@@ -5,7 +5,7 @@
 class A<X extends core::Object* = dynamic> extends core::Object {
   synthetic constructor •() → self::A<self::A::X*>*
     ;
-  method foo<generic-covariant-impl Y extends self::A::X* = self::A::X*>() → dynamic
+  method foo<generic-covariant-impl Y extends self::A::X*>() → dynamic
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
diff --git a/pkg/front_end/testcases/general/bug35470.dart.weak.transformed.expect b/pkg/front_end/testcases/general/bug35470.dart.weak.transformed.expect
index 4bb1bd3..42009f8 100644
--- a/pkg/front_end/testcases/general/bug35470.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/bug35470.dart.weak.transformed.expect
@@ -6,7 +6,7 @@
   synthetic constructor •() → self::A<self::A::X*>*
     : super core::Object::•()
     ;
-  method foo<generic-covariant-impl Y extends self::A::X* = self::A::X*>() → dynamic {}
+  method foo<generic-covariant-impl Y extends self::A::X*>() → dynamic {}
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
diff --git a/pkg/front_end/testcases/general/bug37476.dart.weak.expect b/pkg/front_end/testcases/general/bug37476.dart.weak.expect
index 112e0e4..bd16297 100644
--- a/pkg/front_end/testcases/general/bug37476.dart.weak.expect
+++ b/pkg/front_end/testcases/general/bug37476.dart.weak.expect
@@ -2,13 +2,13 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::num* = core::num*> extends core::Object {
+class A<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     : super core::Object::•()
     ;
   method foo() → <S extends self::A::T* = dynamic>(S*) →* void {
     core::print("foo: T = ${self::A::T*}");
-    return <S extends self::A::T* = self::A::T*>(S* a) → Null {};
+    return <S extends self::A::T*>(S* a) → Null {};
   }
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -21,7 +21,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class B<T extends core::num* = core::num*> extends core::Object {
+class B<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::B<self::B::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/general/bug37476.dart.weak.outline.expect b/pkg/front_end/testcases/general/bug37476.dart.weak.outline.expect
index 7828759..112f56d 100644
--- a/pkg/front_end/testcases/general/bug37476.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/bug37476.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::num* = core::num*> extends core::Object {
+class A<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     ;
   method foo() → <S extends self::A::T* = dynamic>(S*) →* void
@@ -18,7 +18,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class B<T extends core::num* = core::num*> extends core::Object {
+class B<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::B<self::B::T*>*
     ;
   method foo() → (self::B::T*) →* void
diff --git a/pkg/front_end/testcases/general/bug37476.dart.weak.transformed.expect b/pkg/front_end/testcases/general/bug37476.dart.weak.transformed.expect
index 112e0e4..bd16297 100644
--- a/pkg/front_end/testcases/general/bug37476.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/bug37476.dart.weak.transformed.expect
@@ -2,13 +2,13 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::num* = core::num*> extends core::Object {
+class A<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     : super core::Object::•()
     ;
   method foo() → <S extends self::A::T* = dynamic>(S*) →* void {
     core::print("foo: T = ${self::A::T*}");
-    return <S extends self::A::T* = self::A::T*>(S* a) → Null {};
+    return <S extends self::A::T*>(S* a) → Null {};
   }
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -21,7 +21,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class B<T extends core::num* = core::num*> extends core::Object {
+class B<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::B<self::B::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/general/callable_type_variable.dart.weak.expect b/pkg/front_end/testcases/general/callable_type_variable.dart.weak.expect
index a03f477..c56828e 100644
--- a/pkg/front_end/testcases/general/callable_type_variable.dart.weak.expect
+++ b/pkg/front_end/testcases/general/callable_type_variable.dart.weak.expect
@@ -13,7 +13,7 @@
 import self as self;
 import "dart:core" as core;
 
-class Class1<T extends core::Function* = core::Function*> extends core::Object {
+class Class1<T extends core::Function*> extends core::Object {
   generic-covariant-impl field self::Class1::T* field;
   constructor •(self::Class1::T* field) → self::Class1<self::Class1::T*>*
     : self::Class1::field = field, super core::Object::•()
@@ -36,7 +36,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Class2<T extends (core::int*) →* core::String* = (core::int*) →* core::String*> extends core::Object {
+class Class2<T extends (core::int*) →* core::String*> extends core::Object {
   generic-covariant-impl field self::Class2::T* field;
   constructor •(self::Class2::T* field) → self::Class2<self::Class2::T*>*
     : self::Class2::field = field, super core::Object::•()
diff --git a/pkg/front_end/testcases/general/callable_type_variable.dart.weak.outline.expect b/pkg/front_end/testcases/general/callable_type_variable.dart.weak.outline.expect
index 139ef5e..654c962 100644
--- a/pkg/front_end/testcases/general/callable_type_variable.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/callable_type_variable.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class Class1<T extends core::Function* = core::Function*> extends core::Object {
+class Class1<T extends core::Function*> extends core::Object {
   generic-covariant-impl field self::Class1::T* field;
   constructor •(self::Class1::T* field) → self::Class1<self::Class1::T*>*
     ;
@@ -19,7 +19,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Class2<T extends (core::int*) →* core::String* = (core::int*) →* core::String*> extends core::Object {
+class Class2<T extends (core::int*) →* core::String*> extends core::Object {
   generic-covariant-impl field self::Class2::T* field;
   constructor •(self::Class2::T* field) → self::Class2<self::Class2::T*>*
     ;
diff --git a/pkg/front_end/testcases/general/callable_type_variable.dart.weak.transformed.expect b/pkg/front_end/testcases/general/callable_type_variable.dart.weak.transformed.expect
index 6388442..f7b5cfc 100644
--- a/pkg/front_end/testcases/general/callable_type_variable.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/callable_type_variable.dart.weak.transformed.expect
@@ -13,7 +13,7 @@
 import self as self;
 import "dart:core" as core;
 
-class Class1<T extends core::Function* = core::Function*> extends core::Object {
+class Class1<T extends core::Function*> extends core::Object {
   generic-covariant-impl field self::Class1::T* field;
   constructor •(self::Class1::T* field) → self::Class1<self::Class1::T*>*
     : self::Class1::field = field, super core::Object::•()
@@ -36,7 +36,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Class2<T extends (core::int*) →* core::String* = (core::int*) →* core::String*> extends core::Object {
+class Class2<T extends (core::int*) →* core::String*> extends core::Object {
   generic-covariant-impl field self::Class2::T* field;
   constructor •(self::Class2::T* field) → self::Class2<self::Class2::T*>*
     : self::Class2::field = field, super core::Object::•()
diff --git a/pkg/front_end/testcases/general/clone_function_type.dart.weak.expect b/pkg/front_end/testcases/general/clone_function_type.dart.weak.expect
index a8b62fb..7453dc4 100644
--- a/pkg/front_end/testcases/general/clone_function_type.dart.weak.expect
+++ b/pkg/front_end/testcases/general/clone_function_type.dart.weak.expect
@@ -513,7 +513,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Am2<X extends () →* dynamic = () →* dynamic, Y extends core::Object* = dynamic> extends core::Object {
+class Am2<X extends () →* dynamic, Y extends core::Object* = dynamic> extends core::Object {
   synthetic constructor •() → self::Am2<self::Am2::X*, self::Am2::Y*>*
     : super core::Object::•()
     ;
@@ -1128,8 +1128,8 @@
     : super self::_Km3&Object&Am3::•()
     ;
 }
-class Af1<X extends (core::int*) →* dynamic = (core::int*) →* dynamic> extends core::Object {
-  static factory foo<X extends (core::int*) →* dynamic = (core::int*) →* dynamic>() → self::Af1<self::Af1::foo::X*>*
+class Af1<X extends (core::int*) →* dynamic> extends core::Object {
+  static factory foo<X extends (core::int*) →* dynamic>() → self::Af1<self::Af1::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1142,8 +1142,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Bf1<X extends (core::int*) →* dynamic = (core::int*) →* dynamic> extends core::Object {
-  static factory foo<X extends (core::int*) →* dynamic = (core::int*) →* dynamic>() → self::Bf1<self::Bf1::foo::X*>*
+class Bf1<X extends (core::int*) →* dynamic> extends core::Object {
+  static factory foo<X extends (core::int*) →* dynamic>() → self::Bf1<self::Bf1::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1156,8 +1156,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Cf1<X extends () →* core::int* = () →* core::int*> extends core::Object {
-  static factory foo<X extends () →* core::int* = () →* core::int*>() → self::Cf1<self::Cf1::foo::X*>*
+class Cf1<X extends () →* core::int*> extends core::Object {
+  static factory foo<X extends () →* core::int*>() → self::Cf1<self::Cf1::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1170,8 +1170,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Df1<X extends () →* dynamic = () →* dynamic> extends core::Object {
-  static factory foo<X extends () →* dynamic = () →* dynamic>() → self::Df1<self::Df1::foo::X*>*
+class Df1<X extends () →* dynamic> extends core::Object {
+  static factory foo<X extends () →* dynamic>() → self::Df1<self::Df1::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1184,8 +1184,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Ef1<X extends () →* dynamic = () →* dynamic> extends core::Object {
-  static factory foo<X extends () →* dynamic = () →* dynamic>() → self::Ef1<self::Ef1::foo::X*>*
+class Ef1<X extends () →* dynamic> extends core::Object {
+  static factory foo<X extends () →* dynamic>() → self::Ef1<self::Ef1::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1198,8 +1198,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Ff1<X extends ({x: core::int*}) →* dynamic = ({x: core::int*}) →* dynamic> extends core::Object {
-  static factory foo<X extends ({x: core::int*}) →* dynamic = ({x: core::int*}) →* dynamic>() → self::Ff1<self::Ff1::foo::X*>*
+class Ff1<X extends ({x: core::int*}) →* dynamic> extends core::Object {
+  static factory foo<X extends ({x: core::int*}) →* dynamic>() → self::Ff1<self::Ff1::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1212,8 +1212,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Gf1<X extends ([core::int*]) →* dynamic = ([core::int*]) →* dynamic> extends core::Object {
-  static factory foo<X extends ([core::int*]) →* dynamic = ([core::int*]) →* dynamic>() → self::Gf1<self::Gf1::foo::X*>*
+class Gf1<X extends ([core::int*]) →* dynamic> extends core::Object {
+  static factory foo<X extends ([core::int*]) →* dynamic>() → self::Gf1<self::Gf1::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1226,8 +1226,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Hf1<X extends ([core::int*]) →* dynamic = ([core::int*]) →* dynamic> extends core::Object {
-  static factory foo<X extends ([core::int*]) →* dynamic = ([core::int*]) →* dynamic>() → self::Hf1<self::Hf1::foo::X*>*
+class Hf1<X extends ([core::int*]) →* dynamic> extends core::Object {
+  static factory foo<X extends ([core::int*]) →* dynamic>() → self::Hf1<self::Hf1::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1240,8 +1240,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class If1<X extends core::Function* = core::Function*> extends core::Object {
-  static factory foo<X extends core::Function* = core::Function*>() → self::If1<self::If1::foo::X*>*
+class If1<X extends core::Function*> extends core::Object {
+  static factory foo<X extends core::Function*>() → self::If1<self::If1::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1254,8 +1254,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Jf1<X extends (core::Function*) →* dynamic = (core::Function*) →* dynamic> extends core::Object {
-  static factory foo<X extends (core::Function*) →* dynamic = (core::Function*) →* dynamic>() → self::Jf1<self::Jf1::foo::X*>*
+class Jf1<X extends (core::Function*) →* dynamic> extends core::Object {
+  static factory foo<X extends (core::Function*) →* dynamic>() → self::Jf1<self::Jf1::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1268,8 +1268,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Kf1<X extends () →* (() →* core::Function*) →* dynamic = () →* (() →* core::Function*) →* dynamic> extends core::Object {
-  static factory foo<X extends () →* (() →* core::Function*) →* dynamic = () →* (() →* core::Function*) →* dynamic>() → self::Kf1<self::Kf1::foo::X*>*
+class Kf1<X extends () →* (() →* core::Function*) →* dynamic> extends core::Object {
+  static factory foo<X extends () →* (() →* core::Function*) →* dynamic>() → self::Kf1<self::Kf1::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1282,8 +1282,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Bf2<X extends (core::int*) →* dynamic = (core::int*) →* dynamic> extends core::Object {
-  static factory foo<X extends (core::int*) →* dynamic = (core::int*) →* dynamic>() → self::Bf2<self::Bf2::foo::X*>*
+class Bf2<X extends (core::int*) →* dynamic> extends core::Object {
+  static factory foo<X extends (core::int*) →* dynamic>() → self::Bf2<self::Bf2::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1296,8 +1296,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Cf2<X extends (core::int*) →* dynamic = (core::int*) →* dynamic> extends core::Object {
-  static factory foo<X extends (core::int*) →* dynamic = (core::int*) →* dynamic>() → self::Cf2<self::Cf2::foo::X*>*
+class Cf2<X extends (core::int*) →* dynamic> extends core::Object {
+  static factory foo<X extends (core::int*) →* dynamic>() → self::Cf2<self::Cf2::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1310,8 +1310,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Df2<X extends () →* core::int* = () →* core::int*> extends core::Object {
-  static factory foo<X extends () →* core::int* = () →* core::int*>() → self::Df2<self::Df2::foo::X*>*
+class Df2<X extends () →* core::int*> extends core::Object {
+  static factory foo<X extends () →* core::int*>() → self::Df2<self::Df2::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1324,8 +1324,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Ef2<X extends () →* dynamic = () →* dynamic> extends core::Object {
-  static factory foo<X extends () →* dynamic = () →* dynamic>() → self::Ef2<self::Ef2::foo::X*>*
+class Ef2<X extends () →* dynamic> extends core::Object {
+  static factory foo<X extends () →* dynamic>() → self::Ef2<self::Ef2::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1338,8 +1338,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Ff2<X extends () →* dynamic = () →* dynamic> extends core::Object {
-  static factory foo<X extends () →* dynamic = () →* dynamic>() → self::Ff2<self::Ff2::foo::X*>*
+class Ff2<X extends () →* dynamic> extends core::Object {
+  static factory foo<X extends () →* dynamic>() → self::Ff2<self::Ff2::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1352,8 +1352,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Gf2<X extends ({x: core::int*}) →* dynamic = ({x: core::int*}) →* dynamic> extends core::Object {
-  static factory foo<X extends ({x: core::int*}) →* dynamic = ({x: core::int*}) →* dynamic>() → self::Gf2<self::Gf2::foo::X*>*
+class Gf2<X extends ({x: core::int*}) →* dynamic> extends core::Object {
+  static factory foo<X extends ({x: core::int*}) →* dynamic>() → self::Gf2<self::Gf2::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1366,8 +1366,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Hf2<X extends ([core::int*]) →* dynamic = ([core::int*]) →* dynamic> extends core::Object {
-  static factory foo<X extends ([core::int*]) →* dynamic = ([core::int*]) →* dynamic>() → self::Hf2<self::Hf2::foo::X*>*
+class Hf2<X extends ([core::int*]) →* dynamic> extends core::Object {
+  static factory foo<X extends ([core::int*]) →* dynamic>() → self::Hf2<self::Hf2::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1380,8 +1380,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class If2<X extends ([core::int*]) →* dynamic = ([core::int*]) →* dynamic> extends core::Object {
-  static factory foo<X extends ([core::int*]) →* dynamic = ([core::int*]) →* dynamic>() → self::If2<self::If2::foo::X*>*
+class If2<X extends ([core::int*]) →* dynamic> extends core::Object {
+  static factory foo<X extends ([core::int*]) →* dynamic>() → self::If2<self::If2::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1394,8 +1394,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Jf2<X extends (core::Function*) →* dynamic = (core::Function*) →* dynamic> extends core::Object {
-  static factory foo<X extends (core::Function*) →* dynamic = (core::Function*) →* dynamic>() → self::Jf2<self::Jf2::foo::X*>*
+class Jf2<X extends (core::Function*) →* dynamic> extends core::Object {
+  static factory foo<X extends (core::Function*) →* dynamic>() → self::Jf2<self::Jf2::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1408,8 +1408,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Kf2<X extends () →* (() →* core::Function*) →* dynamic = () →* (() →* core::Function*) →* dynamic> extends core::Object {
-  static factory foo<X extends () →* (() →* core::Function*) →* dynamic = () →* (() →* core::Function*) →* dynamic>() → self::Kf2<self::Kf2::foo::X*>*
+class Kf2<X extends () →* (() →* core::Function*) →* dynamic> extends core::Object {
+  static factory foo<X extends () →* (() →* core::Function*) →* dynamic>() → self::Kf2<self::Kf2::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
diff --git a/pkg/front_end/testcases/general/clone_function_type.dart.weak.outline.expect b/pkg/front_end/testcases/general/clone_function_type.dart.weak.outline.expect
index def0418..cf63a80 100644
--- a/pkg/front_end/testcases/general/clone_function_type.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/clone_function_type.dart.weak.outline.expect
@@ -501,7 +501,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Am2<X extends () →* dynamic = () →* dynamic, Y extends core::Object* = dynamic> extends core::Object {
+class Am2<X extends () →* dynamic, Y extends core::Object* = dynamic> extends core::Object {
   synthetic constructor •() → self::Am2<self::Am2::X*, self::Am2::Y*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
@@ -1093,8 +1093,8 @@
   synthetic constructor •() → self::Km3<self::Km3::Z*>*
     ;
 }
-class Af1<X extends (core::int*) →* dynamic = (core::int*) →* dynamic> extends core::Object {
-  static factory foo<X extends (core::int*) →* dynamic = (core::int*) →* dynamic>() → self::Af1<self::Af1::foo::X*>*
+class Af1<X extends (core::int*) →* dynamic> extends core::Object {
+  static factory foo<X extends (core::int*) →* dynamic>() → self::Af1<self::Af1::foo::X*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1107,8 +1107,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Bf1<X extends (core::int*) →* dynamic = (core::int*) →* dynamic> extends core::Object {
-  static factory foo<X extends (core::int*) →* dynamic = (core::int*) →* dynamic>() → self::Bf1<self::Bf1::foo::X*>*
+class Bf1<X extends (core::int*) →* dynamic> extends core::Object {
+  static factory foo<X extends (core::int*) →* dynamic>() → self::Bf1<self::Bf1::foo::X*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1121,8 +1121,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Cf1<X extends () →* core::int* = () →* core::int*> extends core::Object {
-  static factory foo<X extends () →* core::int* = () →* core::int*>() → self::Cf1<self::Cf1::foo::X*>*
+class Cf1<X extends () →* core::int*> extends core::Object {
+  static factory foo<X extends () →* core::int*>() → self::Cf1<self::Cf1::foo::X*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1135,8 +1135,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Df1<X extends () →* dynamic = () →* dynamic> extends core::Object {
-  static factory foo<X extends () →* dynamic = () →* dynamic>() → self::Df1<self::Df1::foo::X*>*
+class Df1<X extends () →* dynamic> extends core::Object {
+  static factory foo<X extends () →* dynamic>() → self::Df1<self::Df1::foo::X*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1149,8 +1149,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Ef1<X extends () →* dynamic = () →* dynamic> extends core::Object {
-  static factory foo<X extends () →* dynamic = () →* dynamic>() → self::Ef1<self::Ef1::foo::X*>*
+class Ef1<X extends () →* dynamic> extends core::Object {
+  static factory foo<X extends () →* dynamic>() → self::Ef1<self::Ef1::foo::X*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1163,8 +1163,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Ff1<X extends ({x: core::int*}) →* dynamic = ({x: core::int*}) →* dynamic> extends core::Object {
-  static factory foo<X extends ({x: core::int*}) →* dynamic = ({x: core::int*}) →* dynamic>() → self::Ff1<self::Ff1::foo::X*>*
+class Ff1<X extends ({x: core::int*}) →* dynamic> extends core::Object {
+  static factory foo<X extends ({x: core::int*}) →* dynamic>() → self::Ff1<self::Ff1::foo::X*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1177,8 +1177,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Gf1<X extends ([core::int*]) →* dynamic = ([core::int*]) →* dynamic> extends core::Object {
-  static factory foo<X extends ([core::int*]) →* dynamic = ([core::int*]) →* dynamic>() → self::Gf1<self::Gf1::foo::X*>*
+class Gf1<X extends ([core::int*]) →* dynamic> extends core::Object {
+  static factory foo<X extends ([core::int*]) →* dynamic>() → self::Gf1<self::Gf1::foo::X*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1191,8 +1191,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Hf1<X extends ([core::int*]) →* dynamic = ([core::int*]) →* dynamic> extends core::Object {
-  static factory foo<X extends ([core::int*]) →* dynamic = ([core::int*]) →* dynamic>() → self::Hf1<self::Hf1::foo::X*>*
+class Hf1<X extends ([core::int*]) →* dynamic> extends core::Object {
+  static factory foo<X extends ([core::int*]) →* dynamic>() → self::Hf1<self::Hf1::foo::X*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1205,8 +1205,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class If1<X extends core::Function* = core::Function*> extends core::Object {
-  static factory foo<X extends core::Function* = core::Function*>() → self::If1<self::If1::foo::X*>*
+class If1<X extends core::Function*> extends core::Object {
+  static factory foo<X extends core::Function*>() → self::If1<self::If1::foo::X*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1219,8 +1219,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Jf1<X extends (core::Function*) →* dynamic = (core::Function*) →* dynamic> extends core::Object {
-  static factory foo<X extends (core::Function*) →* dynamic = (core::Function*) →* dynamic>() → self::Jf1<self::Jf1::foo::X*>*
+class Jf1<X extends (core::Function*) →* dynamic> extends core::Object {
+  static factory foo<X extends (core::Function*) →* dynamic>() → self::Jf1<self::Jf1::foo::X*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1233,8 +1233,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Kf1<X extends () →* (() →* core::Function*) →* dynamic = () →* (() →* core::Function*) →* dynamic> extends core::Object {
-  static factory foo<X extends () →* (() →* core::Function*) →* dynamic = () →* (() →* core::Function*) →* dynamic>() → self::Kf1<self::Kf1::foo::X*>*
+class Kf1<X extends () →* (() →* core::Function*) →* dynamic> extends core::Object {
+  static factory foo<X extends () →* (() →* core::Function*) →* dynamic>() → self::Kf1<self::Kf1::foo::X*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1247,8 +1247,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Bf2<X extends (core::int*) →* dynamic = (core::int*) →* dynamic> extends core::Object {
-  static factory foo<X extends (core::int*) →* dynamic = (core::int*) →* dynamic>() → self::Bf2<self::Bf2::foo::X*>*
+class Bf2<X extends (core::int*) →* dynamic> extends core::Object {
+  static factory foo<X extends (core::int*) →* dynamic>() → self::Bf2<self::Bf2::foo::X*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1261,8 +1261,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Cf2<X extends (core::int*) →* dynamic = (core::int*) →* dynamic> extends core::Object {
-  static factory foo<X extends (core::int*) →* dynamic = (core::int*) →* dynamic>() → self::Cf2<self::Cf2::foo::X*>*
+class Cf2<X extends (core::int*) →* dynamic> extends core::Object {
+  static factory foo<X extends (core::int*) →* dynamic>() → self::Cf2<self::Cf2::foo::X*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1275,8 +1275,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Df2<X extends () →* core::int* = () →* core::int*> extends core::Object {
-  static factory foo<X extends () →* core::int* = () →* core::int*>() → self::Df2<self::Df2::foo::X*>*
+class Df2<X extends () →* core::int*> extends core::Object {
+  static factory foo<X extends () →* core::int*>() → self::Df2<self::Df2::foo::X*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1289,8 +1289,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Ef2<X extends () →* dynamic = () →* dynamic> extends core::Object {
-  static factory foo<X extends () →* dynamic = () →* dynamic>() → self::Ef2<self::Ef2::foo::X*>*
+class Ef2<X extends () →* dynamic> extends core::Object {
+  static factory foo<X extends () →* dynamic>() → self::Ef2<self::Ef2::foo::X*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1303,8 +1303,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Ff2<X extends () →* dynamic = () →* dynamic> extends core::Object {
-  static factory foo<X extends () →* dynamic = () →* dynamic>() → self::Ff2<self::Ff2::foo::X*>*
+class Ff2<X extends () →* dynamic> extends core::Object {
+  static factory foo<X extends () →* dynamic>() → self::Ff2<self::Ff2::foo::X*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1317,8 +1317,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Gf2<X extends ({x: core::int*}) →* dynamic = ({x: core::int*}) →* dynamic> extends core::Object {
-  static factory foo<X extends ({x: core::int*}) →* dynamic = ({x: core::int*}) →* dynamic>() → self::Gf2<self::Gf2::foo::X*>*
+class Gf2<X extends ({x: core::int*}) →* dynamic> extends core::Object {
+  static factory foo<X extends ({x: core::int*}) →* dynamic>() → self::Gf2<self::Gf2::foo::X*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1331,8 +1331,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Hf2<X extends ([core::int*]) →* dynamic = ([core::int*]) →* dynamic> extends core::Object {
-  static factory foo<X extends ([core::int*]) →* dynamic = ([core::int*]) →* dynamic>() → self::Hf2<self::Hf2::foo::X*>*
+class Hf2<X extends ([core::int*]) →* dynamic> extends core::Object {
+  static factory foo<X extends ([core::int*]) →* dynamic>() → self::Hf2<self::Hf2::foo::X*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1345,8 +1345,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class If2<X extends ([core::int*]) →* dynamic = ([core::int*]) →* dynamic> extends core::Object {
-  static factory foo<X extends ([core::int*]) →* dynamic = ([core::int*]) →* dynamic>() → self::If2<self::If2::foo::X*>*
+class If2<X extends ([core::int*]) →* dynamic> extends core::Object {
+  static factory foo<X extends ([core::int*]) →* dynamic>() → self::If2<self::If2::foo::X*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1359,8 +1359,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Jf2<X extends (core::Function*) →* dynamic = (core::Function*) →* dynamic> extends core::Object {
-  static factory foo<X extends (core::Function*) →* dynamic = (core::Function*) →* dynamic>() → self::Jf2<self::Jf2::foo::X*>*
+class Jf2<X extends (core::Function*) →* dynamic> extends core::Object {
+  static factory foo<X extends (core::Function*) →* dynamic>() → self::Jf2<self::Jf2::foo::X*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1373,8 +1373,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Kf2<X extends () →* (() →* core::Function*) →* dynamic = () →* (() →* core::Function*) →* dynamic> extends core::Object {
-  static factory foo<X extends () →* (() →* core::Function*) →* dynamic = () →* (() →* core::Function*) →* dynamic>() → self::Kf2<self::Kf2::foo::X*>*
+class Kf2<X extends () →* (() →* core::Function*) →* dynamic> extends core::Object {
+  static factory foo<X extends () →* (() →* core::Function*) →* dynamic>() → self::Kf2<self::Kf2::foo::X*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
diff --git a/pkg/front_end/testcases/general/clone_function_type.dart.weak.transformed.expect b/pkg/front_end/testcases/general/clone_function_type.dart.weak.transformed.expect
index 7935b39..93e0a13 100644
--- a/pkg/front_end/testcases/general/clone_function_type.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/clone_function_type.dart.weak.transformed.expect
@@ -513,7 +513,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Am2<X extends () →* dynamic = () →* dynamic, Y extends core::Object* = dynamic> extends core::Object {
+class Am2<X extends () →* dynamic, Y extends core::Object* = dynamic> extends core::Object {
   synthetic constructor •() → self::Am2<self::Am2::X*, self::Am2::Y*>*
     : super core::Object::•()
     ;
@@ -1128,8 +1128,8 @@
     : super self::_Km3&Object&Am3::•()
     ;
 }
-class Af1<X extends (core::int*) →* dynamic = (core::int*) →* dynamic> extends core::Object {
-  static factory foo<X extends (core::int*) →* dynamic = (core::int*) →* dynamic>() → self::Af1<self::Af1::foo::X*>*
+class Af1<X extends (core::int*) →* dynamic> extends core::Object {
+  static factory foo<X extends (core::int*) →* dynamic>() → self::Af1<self::Af1::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1142,8 +1142,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Bf1<X extends (core::int*) →* dynamic = (core::int*) →* dynamic> extends core::Object {
-  static factory foo<X extends (core::int*) →* dynamic = (core::int*) →* dynamic>() → self::Bf1<self::Bf1::foo::X*>*
+class Bf1<X extends (core::int*) →* dynamic> extends core::Object {
+  static factory foo<X extends (core::int*) →* dynamic>() → self::Bf1<self::Bf1::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1156,8 +1156,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Cf1<X extends () →* core::int* = () →* core::int*> extends core::Object {
-  static factory foo<X extends () →* core::int* = () →* core::int*>() → self::Cf1<self::Cf1::foo::X*>*
+class Cf1<X extends () →* core::int*> extends core::Object {
+  static factory foo<X extends () →* core::int*>() → self::Cf1<self::Cf1::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1170,8 +1170,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Df1<X extends () →* dynamic = () →* dynamic> extends core::Object {
-  static factory foo<X extends () →* dynamic = () →* dynamic>() → self::Df1<self::Df1::foo::X*>*
+class Df1<X extends () →* dynamic> extends core::Object {
+  static factory foo<X extends () →* dynamic>() → self::Df1<self::Df1::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1184,8 +1184,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Ef1<X extends () →* dynamic = () →* dynamic> extends core::Object {
-  static factory foo<X extends () →* dynamic = () →* dynamic>() → self::Ef1<self::Ef1::foo::X*>*
+class Ef1<X extends () →* dynamic> extends core::Object {
+  static factory foo<X extends () →* dynamic>() → self::Ef1<self::Ef1::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1198,8 +1198,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Ff1<X extends ({x: core::int*}) →* dynamic = ({x: core::int*}) →* dynamic> extends core::Object {
-  static factory foo<X extends ({x: core::int*}) →* dynamic = ({x: core::int*}) →* dynamic>() → self::Ff1<self::Ff1::foo::X*>*
+class Ff1<X extends ({x: core::int*}) →* dynamic> extends core::Object {
+  static factory foo<X extends ({x: core::int*}) →* dynamic>() → self::Ff1<self::Ff1::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1212,8 +1212,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Gf1<X extends ([core::int*]) →* dynamic = ([core::int*]) →* dynamic> extends core::Object {
-  static factory foo<X extends ([core::int*]) →* dynamic = ([core::int*]) →* dynamic>() → self::Gf1<self::Gf1::foo::X*>*
+class Gf1<X extends ([core::int*]) →* dynamic> extends core::Object {
+  static factory foo<X extends ([core::int*]) →* dynamic>() → self::Gf1<self::Gf1::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1226,8 +1226,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Hf1<X extends ([core::int*]) →* dynamic = ([core::int*]) →* dynamic> extends core::Object {
-  static factory foo<X extends ([core::int*]) →* dynamic = ([core::int*]) →* dynamic>() → self::Hf1<self::Hf1::foo::X*>*
+class Hf1<X extends ([core::int*]) →* dynamic> extends core::Object {
+  static factory foo<X extends ([core::int*]) →* dynamic>() → self::Hf1<self::Hf1::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1240,8 +1240,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class If1<X extends core::Function* = core::Function*> extends core::Object {
-  static factory foo<X extends core::Function* = core::Function*>() → self::If1<self::If1::foo::X*>*
+class If1<X extends core::Function*> extends core::Object {
+  static factory foo<X extends core::Function*>() → self::If1<self::If1::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1254,8 +1254,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Jf1<X extends (core::Function*) →* dynamic = (core::Function*) →* dynamic> extends core::Object {
-  static factory foo<X extends (core::Function*) →* dynamic = (core::Function*) →* dynamic>() → self::Jf1<self::Jf1::foo::X*>*
+class Jf1<X extends (core::Function*) →* dynamic> extends core::Object {
+  static factory foo<X extends (core::Function*) →* dynamic>() → self::Jf1<self::Jf1::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1268,8 +1268,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Kf1<X extends () →* (() →* core::Function*) →* dynamic = () →* (() →* core::Function*) →* dynamic> extends core::Object {
-  static factory foo<X extends () →* (() →* core::Function*) →* dynamic = () →* (() →* core::Function*) →* dynamic>() → self::Kf1<self::Kf1::foo::X*>*
+class Kf1<X extends () →* (() →* core::Function*) →* dynamic> extends core::Object {
+  static factory foo<X extends () →* (() →* core::Function*) →* dynamic>() → self::Kf1<self::Kf1::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1282,8 +1282,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Bf2<X extends (core::int*) →* dynamic = (core::int*) →* dynamic> extends core::Object {
-  static factory foo<X extends (core::int*) →* dynamic = (core::int*) →* dynamic>() → self::Bf2<self::Bf2::foo::X*>*
+class Bf2<X extends (core::int*) →* dynamic> extends core::Object {
+  static factory foo<X extends (core::int*) →* dynamic>() → self::Bf2<self::Bf2::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1296,8 +1296,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Cf2<X extends (core::int*) →* dynamic = (core::int*) →* dynamic> extends core::Object {
-  static factory foo<X extends (core::int*) →* dynamic = (core::int*) →* dynamic>() → self::Cf2<self::Cf2::foo::X*>*
+class Cf2<X extends (core::int*) →* dynamic> extends core::Object {
+  static factory foo<X extends (core::int*) →* dynamic>() → self::Cf2<self::Cf2::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1310,8 +1310,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Df2<X extends () →* core::int* = () →* core::int*> extends core::Object {
-  static factory foo<X extends () →* core::int* = () →* core::int*>() → self::Df2<self::Df2::foo::X*>*
+class Df2<X extends () →* core::int*> extends core::Object {
+  static factory foo<X extends () →* core::int*>() → self::Df2<self::Df2::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1324,8 +1324,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Ef2<X extends () →* dynamic = () →* dynamic> extends core::Object {
-  static factory foo<X extends () →* dynamic = () →* dynamic>() → self::Ef2<self::Ef2::foo::X*>*
+class Ef2<X extends () →* dynamic> extends core::Object {
+  static factory foo<X extends () →* dynamic>() → self::Ef2<self::Ef2::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1338,8 +1338,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Ff2<X extends () →* dynamic = () →* dynamic> extends core::Object {
-  static factory foo<X extends () →* dynamic = () →* dynamic>() → self::Ff2<self::Ff2::foo::X*>*
+class Ff2<X extends () →* dynamic> extends core::Object {
+  static factory foo<X extends () →* dynamic>() → self::Ff2<self::Ff2::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1352,8 +1352,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Gf2<X extends ({x: core::int*}) →* dynamic = ({x: core::int*}) →* dynamic> extends core::Object {
-  static factory foo<X extends ({x: core::int*}) →* dynamic = ({x: core::int*}) →* dynamic>() → self::Gf2<self::Gf2::foo::X*>*
+class Gf2<X extends ({x: core::int*}) →* dynamic> extends core::Object {
+  static factory foo<X extends ({x: core::int*}) →* dynamic>() → self::Gf2<self::Gf2::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1366,8 +1366,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Hf2<X extends ([core::int*]) →* dynamic = ([core::int*]) →* dynamic> extends core::Object {
-  static factory foo<X extends ([core::int*]) →* dynamic = ([core::int*]) →* dynamic>() → self::Hf2<self::Hf2::foo::X*>*
+class Hf2<X extends ([core::int*]) →* dynamic> extends core::Object {
+  static factory foo<X extends ([core::int*]) →* dynamic>() → self::Hf2<self::Hf2::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1380,8 +1380,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class If2<X extends ([core::int*]) →* dynamic = ([core::int*]) →* dynamic> extends core::Object {
-  static factory foo<X extends ([core::int*]) →* dynamic = ([core::int*]) →* dynamic>() → self::If2<self::If2::foo::X*>*
+class If2<X extends ([core::int*]) →* dynamic> extends core::Object {
+  static factory foo<X extends ([core::int*]) →* dynamic>() → self::If2<self::If2::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1394,8 +1394,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Jf2<X extends (core::Function*) →* dynamic = (core::Function*) →* dynamic> extends core::Object {
-  static factory foo<X extends (core::Function*) →* dynamic = (core::Function*) →* dynamic>() → self::Jf2<self::Jf2::foo::X*>*
+class Jf2<X extends (core::Function*) →* dynamic> extends core::Object {
+  static factory foo<X extends (core::Function*) →* dynamic>() → self::Jf2<self::Jf2::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -1408,8 +1408,8 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Kf2<X extends () →* (() →* core::Function*) →* dynamic = () →* (() →* core::Function*) →* dynamic> extends core::Object {
-  static factory foo<X extends () →* (() →* core::Function*) →* dynamic = () →* (() →* core::Function*) →* dynamic>() → self::Kf2<self::Kf2::foo::X*>*
+class Kf2<X extends () →* (() →* core::Function*) →* dynamic> extends core::Object {
+  static factory foo<X extends () →* (() →* core::Function*) →* dynamic>() → self::Kf2<self::Kf2::foo::X*>*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
diff --git a/pkg/front_end/testcases/general/complex_class_hierarchy.dart.weak.expect b/pkg/front_end/testcases/general/complex_class_hierarchy.dart.weak.expect
index 19ac8c4..79836e1 100644
--- a/pkg/front_end/testcases/general/complex_class_hierarchy.dart.weak.expect
+++ b/pkg/front_end/testcases/general/complex_class_hierarchy.dart.weak.expect
@@ -32,7 +32,7 @@
     : super self::C::•()
     ;
 }
-class G<T extends self::A* = self::A*> extends core::Object {
+class G<T extends self::A*> extends core::Object {
   synthetic constructor •() → self::G<self::G::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/general/complex_class_hierarchy.dart.weak.outline.expect b/pkg/front_end/testcases/general/complex_class_hierarchy.dart.weak.outline.expect
index f0e2f4b..ec0b3ec 100644
--- a/pkg/front_end/testcases/general/complex_class_hierarchy.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/complex_class_hierarchy.dart.weak.outline.expect
@@ -28,7 +28,7 @@
   synthetic constructor •() → self::D*
     ;
 }
-class G<T extends self::A* = self::A*> extends core::Object {
+class G<T extends self::A*> extends core::Object {
   synthetic constructor •() → self::G<self::G::T*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/general/complex_class_hierarchy.dart.weak.transformed.expect b/pkg/front_end/testcases/general/complex_class_hierarchy.dart.weak.transformed.expect
index 19ac8c4..79836e1 100644
--- a/pkg/front_end/testcases/general/complex_class_hierarchy.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/complex_class_hierarchy.dart.weak.transformed.expect
@@ -32,7 +32,7 @@
     : super self::C::•()
     ;
 }
-class G<T extends self::A* = self::A*> extends core::Object {
+class G<T extends self::A*> extends core::Object {
   synthetic constructor •() → self::G<self::G::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/general/constants/with_unevaluated_agnostic/various.dart.weak.expect b/pkg/front_end/testcases/general/constants/with_unevaluated_agnostic/various.dart.weak.expect
index 5716a4f..3144a2d 100644
--- a/pkg/front_end/testcases/general/constants/with_unevaluated_agnostic/various.dart.weak.expect
+++ b/pkg/front_end/testcases/general/constants/with_unevaluated_agnostic/various.dart.weak.expect
@@ -93,7 +93,7 @@
   operator unary-() → self::C
     return this;
 }
-class Class<T extends self::A = self::A> extends core::Object /*hasConstConstructor*/  {
+class Class<T extends self::A> extends core::Object /*hasConstConstructor*/  {
   const constructor •(self::Class::T t) → self::Class<self::Class::T>
     : super core::Object::•()
     ;
@@ -107,7 +107,7 @@
                                  ^" in t.{self::A::unary-}(){() → self::A} as{TypeError,ForNonNullableByDefault} Never)
     ;
 }
-class Subclass<T extends self::A = self::A> extends self::Class<self::Subclass::T> /*hasConstConstructor*/  {
+class Subclass<T extends self::A> extends self::Class<self::Subclass::T> /*hasConstConstructor*/  {
   const constructor •(dynamic t) → self::Subclass<self::Subclass::T>
     : super self::Class::•(t as{TypeError,ForDynamic,ForNonNullableByDefault} self::Subclass::T)
     ;
diff --git a/pkg/front_end/testcases/general/constants/with_unevaluated_agnostic/various.dart.weak.outline.expect b/pkg/front_end/testcases/general/constants/with_unevaluated_agnostic/various.dart.weak.outline.expect
index 3afb32d..247eb18 100644
--- a/pkg/front_end/testcases/general/constants/with_unevaluated_agnostic/various.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/constants/with_unevaluated_agnostic/various.dart.weak.outline.expect
@@ -65,7 +65,7 @@
   operator unary-() → self::C
     ;
 }
-class Class<T extends self::A = self::A> extends core::Object /*hasConstConstructor*/  {
+class Class<T extends self::A> extends core::Object /*hasConstConstructor*/  {
   const constructor •(self::Class::T t) → self::Class<self::Class::T>
     : super core::Object::•()
     ;
@@ -79,7 +79,7 @@
                                  ^" in t.{self::A::unary-}(){() → self::A} as{TypeError,ForNonNullableByDefault} Never)
     ;
 }
-class Subclass<T extends self::A = self::A> extends self::Class<self::Subclass::T> /*hasConstConstructor*/  {
+class Subclass<T extends self::A> extends self::Class<self::Subclass::T> /*hasConstConstructor*/  {
   const constructor •(dynamic t) → self::Subclass<self::Subclass::T>
     : super self::Class::•(t as{TypeError,ForDynamic,ForNonNullableByDefault} self::Subclass::T)
     ;
diff --git a/pkg/front_end/testcases/general/constants/with_unevaluated_agnostic/various.dart.weak.transformed.expect b/pkg/front_end/testcases/general/constants/with_unevaluated_agnostic/various.dart.weak.transformed.expect
index cc4f2ae..bb6d767 100644
--- a/pkg/front_end/testcases/general/constants/with_unevaluated_agnostic/various.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/constants/with_unevaluated_agnostic/various.dart.weak.transformed.expect
@@ -93,7 +93,7 @@
   operator unary-() → self::C
     return this;
 }
-class Class<T extends self::A = self::A> extends core::Object /*hasConstConstructor*/  {
+class Class<T extends self::A> extends core::Object /*hasConstConstructor*/  {
   const constructor •(self::Class::T t) → self::Class<self::Class::T>
     : super core::Object::•()
     ;
@@ -107,7 +107,7 @@
                                  ^" in t.{self::A::unary-}(){() → self::A} as{TypeError,ForNonNullableByDefault} Never)
     ;
 }
-class Subclass<T extends self::A = self::A> extends self::Class<self::Subclass::T> /*hasConstConstructor*/  {
+class Subclass<T extends self::A> extends self::Class<self::Subclass::T> /*hasConstConstructor*/  {
   const constructor •(dynamic t) → self::Subclass<self::Subclass::T>
     : super self::Class::•(t as{TypeError,ForDynamic,ForNonNullableByDefault} self::Subclass::T)
     ;
diff --git a/pkg/front_end/testcases/general/covariant_type_parameter.dart.weak.expect b/pkg/front_end/testcases/general/covariant_type_parameter.dart.weak.expect
index 02336a0..4ba2d78 100644
--- a/pkg/front_end/testcases/general/covariant_type_parameter.dart.weak.expect
+++ b/pkg/front_end/testcases/general/covariant_type_parameter.dart.weak.expect
@@ -6,7 +6,7 @@
   synthetic constructor •() → self::A<self::A::S*>*
     : super core::Object::•()
     ;
-  method method<generic-covariant-impl T extends self::A::S* = self::A::S*>(generic-covariant-impl self::A::S* s) → void {}
+  method method<generic-covariant-impl T extends self::A::S*>(generic-covariant-impl self::A::S* s) → void {}
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
@@ -22,7 +22,7 @@
   synthetic constructor •() → self::B<self::B::S*>*
     : super core::Object::•()
     ;
-  method method<generic-covariant-impl T extends self::B::S* = self::B::S*>(covariant generic-covariant-impl self::B::S* s) → void {}
+  method method<generic-covariant-impl T extends self::B::S*>(covariant generic-covariant-impl self::B::S* s) → void {}
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
@@ -38,14 +38,14 @@
   synthetic constructor •() → self::C<self::C::S*>*
     : super self::A::•()
     ;
-  forwarding-stub forwarding-semi-stub method method<generic-covariant-impl T extends self::C::S* = self::C::S*>(covariant generic-covariant-impl self::C::S* s) → void
+  forwarding-stub forwarding-semi-stub method method<generic-covariant-impl T extends self::C::S*>(covariant generic-covariant-impl self::C::S* s) → void
     return super.{self::A::method}<self::C::method::T*>(s);
 }
 class D<S extends core::Object* = dynamic> extends self::A<self::D::S*> implements self::B<self::D::S*> {
   synthetic constructor •() → self::D<self::D::S*>*
     : super self::A::•()
     ;
-  forwarding-stub method method<generic-covariant-impl T extends self::D::S* = self::D::S*>(covariant generic-covariant-impl self::D::S* s) → void
+  forwarding-stub method method<generic-covariant-impl T extends self::D::S*>(covariant generic-covariant-impl self::D::S* s) → void
     return super.{self::A::method}<self::D::method::T*>(s);
 }
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/general/covariant_type_parameter.dart.weak.outline.expect b/pkg/front_end/testcases/general/covariant_type_parameter.dart.weak.outline.expect
index 7b6fa81..066d863 100644
--- a/pkg/front_end/testcases/general/covariant_type_parameter.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/covariant_type_parameter.dart.weak.outline.expect
@@ -5,7 +5,7 @@
 class A<S extends core::Object* = dynamic> extends core::Object {
   synthetic constructor •() → self::A<self::A::S*>*
     ;
-  method method<generic-covariant-impl T extends self::A::S* = self::A::S*>(generic-covariant-impl self::A::S* s) → void
+  method method<generic-covariant-impl T extends self::A::S*>(generic-covariant-impl self::A::S* s) → void
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -21,7 +21,7 @@
 class B<S extends core::Object* = dynamic> extends core::Object {
   synthetic constructor •() → self::B<self::B::S*>*
     ;
-  method method<generic-covariant-impl T extends self::B::S* = self::B::S*>(covariant generic-covariant-impl self::B::S* s) → void
+  method method<generic-covariant-impl T extends self::B::S*>(covariant generic-covariant-impl self::B::S* s) → void
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -37,13 +37,13 @@
 class C<S extends core::Object* = dynamic> extends self::A<self::C::S*> implements self::B<self::C::S*> {
   synthetic constructor •() → self::C<self::C::S*>*
     ;
-  forwarding-stub forwarding-semi-stub method method<generic-covariant-impl T extends self::C::S* = self::C::S*>(covariant generic-covariant-impl self::C::S* s) → void
+  forwarding-stub forwarding-semi-stub method method<generic-covariant-impl T extends self::C::S*>(covariant generic-covariant-impl self::C::S* s) → void
     return super.{self::A::method}<self::C::method::T*>(s);
 }
 class D<S extends core::Object* = dynamic> extends self::A<self::D::S*> implements self::B<self::D::S*> {
   synthetic constructor •() → self::D<self::D::S*>*
     ;
-  forwarding-stub method method<generic-covariant-impl T extends self::D::S* = self::D::S*>(covariant generic-covariant-impl self::D::S* s) → void
+  forwarding-stub method method<generic-covariant-impl T extends self::D::S*>(covariant generic-covariant-impl self::D::S* s) → void
     return super.{self::A::method}<self::D::method::T*>(s);
 }
 static method main() → dynamic
diff --git a/pkg/front_end/testcases/general/covariant_type_parameter.dart.weak.transformed.expect b/pkg/front_end/testcases/general/covariant_type_parameter.dart.weak.transformed.expect
index 02336a0..4ba2d78 100644
--- a/pkg/front_end/testcases/general/covariant_type_parameter.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/covariant_type_parameter.dart.weak.transformed.expect
@@ -6,7 +6,7 @@
   synthetic constructor •() → self::A<self::A::S*>*
     : super core::Object::•()
     ;
-  method method<generic-covariant-impl T extends self::A::S* = self::A::S*>(generic-covariant-impl self::A::S* s) → void {}
+  method method<generic-covariant-impl T extends self::A::S*>(generic-covariant-impl self::A::S* s) → void {}
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
@@ -22,7 +22,7 @@
   synthetic constructor •() → self::B<self::B::S*>*
     : super core::Object::•()
     ;
-  method method<generic-covariant-impl T extends self::B::S* = self::B::S*>(covariant generic-covariant-impl self::B::S* s) → void {}
+  method method<generic-covariant-impl T extends self::B::S*>(covariant generic-covariant-impl self::B::S* s) → void {}
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
@@ -38,14 +38,14 @@
   synthetic constructor •() → self::C<self::C::S*>*
     : super self::A::•()
     ;
-  forwarding-stub forwarding-semi-stub method method<generic-covariant-impl T extends self::C::S* = self::C::S*>(covariant generic-covariant-impl self::C::S* s) → void
+  forwarding-stub forwarding-semi-stub method method<generic-covariant-impl T extends self::C::S*>(covariant generic-covariant-impl self::C::S* s) → void
     return super.{self::A::method}<self::C::method::T*>(s);
 }
 class D<S extends core::Object* = dynamic> extends self::A<self::D::S*> implements self::B<self::D::S*> {
   synthetic constructor •() → self::D<self::D::S*>*
     : super self::A::•()
     ;
-  forwarding-stub method method<generic-covariant-impl T extends self::D::S* = self::D::S*>(covariant generic-covariant-impl self::D::S* s) → void
+  forwarding-stub method method<generic-covariant-impl T extends self::D::S*>(covariant generic-covariant-impl self::D::S* s) → void
     return super.{self::A::method}<self::D::method::T*>(s);
 }
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/general/crashes/crash_05/main.dart.weak.expect b/pkg/front_end/testcases/general/crashes/crash_05/main.dart.weak.expect
index cd6f676..ab69e1b 100644
--- a/pkg/front_end/testcases/general/crashes/crash_05/main.dart.weak.expect
+++ b/pkg/front_end/testcases/general/crashes/crash_05/main.dart.weak.expect
@@ -94,5 +94,5 @@
     ;
   method handleEvent(invalid-type event, covariant invalid-type entry) → void {}
 }
-abstract class RenderObjectWithChildMixin<ChildType extends mai::RenderObject = mai::RenderObject> extends mai::RenderObject /*isMixinDeclaration*/  {
+abstract class RenderObjectWithChildMixin<ChildType extends mai::RenderObject> extends mai::RenderObject /*isMixinDeclaration*/  {
 }
diff --git a/pkg/front_end/testcases/general/crashes/crash_05/main.dart.weak.outline.expect b/pkg/front_end/testcases/general/crashes/crash_05/main.dart.weak.outline.expect
index db57999..bac955b 100644
--- a/pkg/front_end/testcases/general/crashes/crash_05/main.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/crashes/crash_05/main.dart.weak.outline.expect
@@ -81,5 +81,5 @@
   method handleEvent(invalid-type event, covariant invalid-type entry) → void
     ;
 }
-abstract class RenderObjectWithChildMixin<ChildType extends mai::RenderObject = mai::RenderObject> extends mai::RenderObject /*isMixinDeclaration*/  {
+abstract class RenderObjectWithChildMixin<ChildType extends mai::RenderObject> extends mai::RenderObject /*isMixinDeclaration*/  {
 }
diff --git a/pkg/front_end/testcases/general/crashes/crash_05/main.dart.weak.transformed.expect b/pkg/front_end/testcases/general/crashes/crash_05/main.dart.weak.transformed.expect
index 6019bb4..89640c3 100644
--- a/pkg/front_end/testcases/general/crashes/crash_05/main.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/crashes/crash_05/main.dart.weak.transformed.expect
@@ -94,5 +94,5 @@
     ;
   method handleEvent(invalid-type event, covariant invalid-type entry) → void {}
 }
-abstract class RenderObjectWithChildMixin<ChildType extends mai::RenderObject = mai::RenderObject> extends mai::RenderObject /*isMixinDeclaration*/  {
+abstract class RenderObjectWithChildMixin<ChildType extends mai::RenderObject> extends mai::RenderObject /*isMixinDeclaration*/  {
 }
diff --git a/pkg/front_end/testcases/general/extend_with_type_variable.dart.weak.expect b/pkg/front_end/testcases/general/extend_with_type_variable.dart.weak.expect
index 9db3393..8ead278 100644
--- a/pkg/front_end/testcases/general/extend_with_type_variable.dart.weak.expect
+++ b/pkg/front_end/testcases/general/extend_with_type_variable.dart.weak.expect
@@ -44,7 +44,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-abstract class _Class1&S&Mixin<T extends core::Object* = dynamic, S extends self::SuperClass* = self::SuperClass*> = core::Object with self::Mixin<self::_Class1&S&Mixin::T*> /*isAnonymousMixin*/  {
+abstract class _Class1&S&Mixin<T extends core::Object* = dynamic, S extends self::SuperClass*> = core::Object with self::Mixin<self::_Class1&S&Mixin::T*> /*isAnonymousMixin*/  {
   synthetic constructor •() → self::_Class1&S&Mixin<self::_Class1&S&Mixin::T*, self::_Class1&S&Mixin::S*>*
     : super core::Object::•()
     ;
@@ -59,7 +59,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Class1<T extends core::Object* = dynamic, S extends self::SuperClass* = self::SuperClass*> extends self::_Class1&S&Mixin<self::Class1::T*, self::Class1::S*> {
+class Class1<T extends core::Object* = dynamic, S extends self::SuperClass*> extends self::_Class1&S&Mixin<self::Class1::T*, self::Class1::S*> {
   synthetic constructor •() → self::Class1<self::Class1::T*, self::Class1::S*>*
     : super self::_Class1&S&Mixin::•()
     ;
diff --git a/pkg/front_end/testcases/general/extend_with_type_variable.dart.weak.outline.expect b/pkg/front_end/testcases/general/extend_with_type_variable.dart.weak.outline.expect
index c70de66..c6193d3 100644
--- a/pkg/front_end/testcases/general/extend_with_type_variable.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/extend_with_type_variable.dart.weak.outline.expect
@@ -43,7 +43,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-abstract class _Class1&S&Mixin<T extends core::Object* = dynamic, S extends self::SuperClass* = self::SuperClass*> = core::Object with self::Mixin<self::_Class1&S&Mixin::T*> /*isAnonymousMixin*/  {
+abstract class _Class1&S&Mixin<T extends core::Object* = dynamic, S extends self::SuperClass*> = core::Object with self::Mixin<self::_Class1&S&Mixin::T*> /*isAnonymousMixin*/  {
   synthetic constructor •() → self::_Class1&S&Mixin<self::_Class1&S&Mixin::T*, self::_Class1&S&Mixin::S*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
@@ -57,7 +57,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Class1<T extends core::Object* = dynamic, S extends self::SuperClass* = self::SuperClass*> extends self::_Class1&S&Mixin<self::Class1::T*, self::Class1::S*> {
+class Class1<T extends core::Object* = dynamic, S extends self::SuperClass*> extends self::_Class1&S&Mixin<self::Class1::T*, self::Class1::S*> {
   synthetic constructor •() → self::Class1<self::Class1::T*, self::Class1::S*>*
     ;
 }
diff --git a/pkg/front_end/testcases/general/extend_with_type_variable.dart.weak.transformed.expect b/pkg/front_end/testcases/general/extend_with_type_variable.dart.weak.transformed.expect
index a62c5b1..3c6fc51 100644
--- a/pkg/front_end/testcases/general/extend_with_type_variable.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/extend_with_type_variable.dart.weak.transformed.expect
@@ -44,7 +44,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-abstract class _Class1&S&Mixin<T extends core::Object* = dynamic, S extends self::SuperClass* = self::SuperClass*> extends core::Object implements self::Mixin<self::_Class1&S&Mixin::T*> /*isAnonymousMixin,isEliminatedMixin*/  {
+abstract class _Class1&S&Mixin<T extends core::Object* = dynamic, S extends self::SuperClass*> extends core::Object implements self::Mixin<self::_Class1&S&Mixin::T*> /*isAnonymousMixin,isEliminatedMixin*/  {
   synthetic constructor •() → self::_Class1&S&Mixin<self::_Class1&S&Mixin::T*, self::_Class1&S&Mixin::S*>*
     : super core::Object::•()
     ;
@@ -59,7 +59,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Class1<T extends core::Object* = dynamic, S extends self::SuperClass* = self::SuperClass*> extends self::_Class1&S&Mixin<self::Class1::T*, self::Class1::S*> {
+class Class1<T extends core::Object* = dynamic, S extends self::SuperClass*> extends self::_Class1&S&Mixin<self::Class1::T*, self::Class1::S*> {
   synthetic constructor •() → self::Class1<self::Class1::T*, self::Class1::S*>*
     : super self::_Class1&S&Mixin::•()
     ;
diff --git a/pkg/front_end/testcases/general/flutter_issue68092/main.dart.weak.expect b/pkg/front_end/testcases/general/flutter_issue68092/main.dart.weak.expect
index 317b261..06e24b0 100644
--- a/pkg/front_end/testcases/general/flutter_issue68092/main.dart.weak.expect
+++ b/pkg/front_end/testcases/general/flutter_issue68092/main.dart.weak.expect
@@ -15,7 +15,7 @@
 import self as mai;
 import "dart:core" as core;
 
-class DynamicDispatchRegistry<T extends core::Function* = core::Function*> extends core::Object {
+class DynamicDispatchRegistry<T extends core::Function*> extends core::Object {
   synthetic constructor •() → mai::DynamicDispatchRegistry<mai::DynamicDispatchRegistry::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/general/flutter_issue68092/main.dart.weak.outline.expect b/pkg/front_end/testcases/general/flutter_issue68092/main.dart.weak.outline.expect
index cfc2e45..63c1b76 100644
--- a/pkg/front_end/testcases/general/flutter_issue68092/main.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/flutter_issue68092/main.dart.weak.outline.expect
@@ -10,7 +10,7 @@
 import self as self2;
 import "dart:core" as core;
 
-class DynamicDispatchRegistry<T extends core::Function* = core::Function*> extends core::Object {
+class DynamicDispatchRegistry<T extends core::Function*> extends core::Object {
   synthetic constructor •() → self2::DynamicDispatchRegistry<self2::DynamicDispatchRegistry::T*>*
     ;
   method register(generic-covariant-impl self2::DynamicDispatchRegistry::T* function) → self2::DynamicDispatchRegistry::T*
diff --git a/pkg/front_end/testcases/general/flutter_issue68092/main.dart.weak.transformed.expect b/pkg/front_end/testcases/general/flutter_issue68092/main.dart.weak.transformed.expect
index 317b261..06e24b0 100644
--- a/pkg/front_end/testcases/general/flutter_issue68092/main.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/flutter_issue68092/main.dart.weak.transformed.expect
@@ -15,7 +15,7 @@
 import self as mai;
 import "dart:core" as core;
 
-class DynamicDispatchRegistry<T extends core::Function* = core::Function*> extends core::Object {
+class DynamicDispatchRegistry<T extends core::Function*> extends core::Object {
   synthetic constructor •() → mai::DynamicDispatchRegistry<mai::DynamicDispatchRegistry::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/general/function_invocation_bounds.dart.weak.expect b/pkg/front_end/testcases/general/function_invocation_bounds.dart.weak.expect
index ea6f457..fa6936b 100644
--- a/pkg/front_end/testcases/general/function_invocation_bounds.dart.weak.expect
+++ b/pkg/front_end/testcases/general/function_invocation_bounds.dart.weak.expect
@@ -35,7 +35,7 @@
 
 typedef G<invariant T extends core::Object? = dynamic> = (T%) → T%;
 static method test() → dynamic {
-  function local<T extends core::num = core::num>(T t) → T
+  function local<T extends core::num>(T t) → T
     return t;
   local.call<core::String>("");
   local.call<core::String>(throw "");
@@ -44,7 +44,7 @@
   let final Never #t1 = invalid-expression "pkg/front_end/testcases/general/function_invocation_bounds.dart:13:8: Error: Expected 1 type arguments.
   local<int, String>(throw '');
        ^" in local.call<core::int, core::String>(throw "");
-  <T extends core::num = core::num>(T) → T f = local;
+  <T extends core::num>(T) → T f = local;
   f.call<core::String>("");
   f.call<core::String>(throw "");
   f.call<core::int>(0);
diff --git a/pkg/front_end/testcases/general/function_type_assignments.dart.weak.expect b/pkg/front_end/testcases/general/function_type_assignments.dart.weak.expect
index a1f9842..0d92c04 100644
--- a/pkg/front_end/testcases/general/function_type_assignments.dart.weak.expect
+++ b/pkg/front_end/testcases/general/function_type_assignments.dart.weak.expect
@@ -32,7 +32,7 @@
            ^" in (#C3) as{TypeError} core::String*;
 static method identity<T extends core::Object* = dynamic>(self::identity::T* t) → self::identity::T*
   return t;
-static method identityObject<T extends core::Object* = core::Object*>(self::identityObject::T* t) → self::identityObject::T*
+static method identityObject<T extends core::Object*>(self::identityObject::T* t) → self::identityObject::T*
   return t;
 static method identityList<T extends core::List<self::identityList::T*>* = core::List<dynamic>*>(self::identityList::T* t) → self::identityList::T*
   return t;
diff --git a/pkg/front_end/testcases/general/function_type_assignments.dart.weak.outline.expect b/pkg/front_end/testcases/general/function_type_assignments.dart.weak.outline.expect
index 1e430dd..3d00d77 100644
--- a/pkg/front_end/testcases/general/function_type_assignments.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/function_type_assignments.dart.weak.outline.expect
@@ -7,7 +7,7 @@
 static field core::String* z;
 static method identity<T extends core::Object* = dynamic>(self::identity::T* t) → self::identity::T*
   ;
-static method identityObject<T extends core::Object* = core::Object*>(self::identityObject::T* t) → self::identityObject::T*
+static method identityObject<T extends core::Object*>(self::identityObject::T* t) → self::identityObject::T*
   ;
 static method identityList<T extends core::List<self::identityList::T*>* = core::List<dynamic>*>(self::identityList::T* t) → self::identityList::T*
   ;
diff --git a/pkg/front_end/testcases/general/function_type_assignments.dart.weak.transformed.expect b/pkg/front_end/testcases/general/function_type_assignments.dart.weak.transformed.expect
index a1f9842..0d92c04 100644
--- a/pkg/front_end/testcases/general/function_type_assignments.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/function_type_assignments.dart.weak.transformed.expect
@@ -32,7 +32,7 @@
            ^" in (#C3) as{TypeError} core::String*;
 static method identity<T extends core::Object* = dynamic>(self::identity::T* t) → self::identity::T*
   return t;
-static method identityObject<T extends core::Object* = core::Object*>(self::identityObject::T* t) → self::identityObject::T*
+static method identityObject<T extends core::Object*>(self::identityObject::T* t) → self::identityObject::T*
   return t;
 static method identityList<T extends core::List<self::identityList::T*>* = core::List<dynamic>*>(self::identityList::T* t) → self::identityList::T*
   return t;
diff --git a/pkg/front_end/testcases/general/generic_function_type_in_message.dart.weak.expect b/pkg/front_end/testcases/general/generic_function_type_in_message.dart.weak.expect
index 0b9eef2..96838f0 100644
--- a/pkg/front_end/testcases/general/generic_function_type_in_message.dart.weak.expect
+++ b/pkg/front_end/testcases/general/generic_function_type_in_message.dart.weak.expect
@@ -9,7 +9,7 @@
 import self as self;
 import "dart:core" as core;
 
-static method add<A extends core::num* = core::num*, B extends core::num* = core::num*>(self::add::A* a, self::add::B* b) → core::num*
+static method add<A extends core::num*, B extends core::num*>(self::add::A* a, self::add::B* b) → core::num*
   return a.{core::num::+}(b);
 static method test() → dynamic {
   core::int* x = let final Never* #t1 = invalid-expression "pkg/front_end/testcases/general/generic_function_type_in_message.dart:8:11: Error: A value of type 'num Function<A extends num, B extends num>(A, B)' can't be assigned to a variable of type 'int'.
diff --git a/pkg/front_end/testcases/general/generic_function_type_in_message.dart.weak.outline.expect b/pkg/front_end/testcases/general/generic_function_type_in_message.dart.weak.outline.expect
index c236efd..36becbd 100644
--- a/pkg/front_end/testcases/general/generic_function_type_in_message.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/generic_function_type_in_message.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-static method add<A extends core::num* = core::num*, B extends core::num* = core::num*>(self::add::A* a, self::add::B* b) → core::num*
+static method add<A extends core::num*, B extends core::num*>(self::add::A* a, self::add::B* b) → core::num*
   ;
 static method test() → dynamic
   ;
diff --git a/pkg/front_end/testcases/general/generic_function_type_in_message.dart.weak.transformed.expect b/pkg/front_end/testcases/general/generic_function_type_in_message.dart.weak.transformed.expect
index 0b9eef2..96838f0 100644
--- a/pkg/front_end/testcases/general/generic_function_type_in_message.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/generic_function_type_in_message.dart.weak.transformed.expect
@@ -9,7 +9,7 @@
 import self as self;
 import "dart:core" as core;
 
-static method add<A extends core::num* = core::num*, B extends core::num* = core::num*>(self::add::A* a, self::add::B* b) → core::num*
+static method add<A extends core::num*, B extends core::num*>(self::add::A* a, self::add::B* b) → core::num*
   return a.{core::num::+}(b);
 static method test() → dynamic {
   core::int* x = let final Never* #t1 = invalid-expression "pkg/front_end/testcases/general/generic_function_type_in_message.dart:8:11: Error: A value of type 'num Function<A extends num, B extends num>(A, B)' can't be assigned to a variable of type 'int'.
diff --git a/pkg/front_end/testcases/general/generic_function_typedef.dart.weak.expect b/pkg/front_end/testcases/general/generic_function_typedef.dart.weak.expect
index adf2f0d..509ac9e 100644
--- a/pkg/front_end/testcases/general/generic_function_typedef.dart.weak.expect
+++ b/pkg/front_end/testcases/general/generic_function_typedef.dart.weak.expect
@@ -3,11 +3,11 @@
 import "dart:core" as core;
 
 typedef E1<unrelated T extends core::Object* = dynamic> = () →* void;
-typedef E2<unrelated T extends core::num* = core::num*> = () →* void;
+typedef E2<unrelated T extends core::num*> = () →* void;
 typedef E3<unrelated T extends core::Object* = dynamic, unrelated S extends core::Object* = dynamic> = () →* void;
-typedef E4<unrelated T extends core::num* = core::num*, unrelated S extends core::num* = core::num*> = () →* void;
-typedef E5<unrelated T extends S* = core::num*, unrelated S extends core::num* = core::num*> = () →* void;
-typedef E6<unrelated T extends core::num* = core::num*, unrelated S extends T* = core::num*> = () →* void;
+typedef E4<unrelated T extends core::num*, unrelated S extends core::num*> = () →* void;
+typedef E5<unrelated T extends S* = core::num*, unrelated S extends core::num*> = () →* void;
+typedef E6<unrelated T extends core::num*, unrelated S extends T* = core::num*> = () →* void;
 typedef F1 = <T extends core::Object* = dynamic>() →* void;
 typedef F2 = <T extends core::num* = dynamic>() →* void;
 typedef F3 = <T extends core::Object* = dynamic, S extends core::Object* = dynamic>() →* void;
@@ -15,11 +15,11 @@
 typedef F5 = <T extends S* = dynamic, S extends core::num* = dynamic>() →* void;
 typedef F6 = <T extends core::num* = dynamic, S extends T* = dynamic>() →* void;
 typedef G1<invariant X extends core::Object* = dynamic> = <T extends X* = dynamic>() →* void;
-typedef G2<invariant X extends core::num* = core::num*> = <T extends X* = dynamic>() →* void;
+typedef G2<invariant X extends core::num*> = <T extends X* = dynamic>() →* void;
 typedef G3<invariant X extends core::Object* = dynamic, invariant Y extends core::Object* = dynamic> = <T extends X* = dynamic, S extends Y* = dynamic>() →* void;
-typedef G4<invariant X extends core::num* = core::num*, invariant Y extends core::num* = core::num*> = <T extends X* = dynamic, S extends Y* = dynamic>() →* void;
-typedef G5<invariant X extends core::num* = core::num*> = <T extends S* = dynamic, S extends X* = dynamic>() →* void;
-typedef G6<invariant X extends core::num* = core::num*> = <T extends X* = dynamic, S extends T* = dynamic>() →* void;
+typedef G4<invariant X extends core::num*, invariant Y extends core::num*> = <T extends X* = dynamic, S extends Y* = dynamic>() →* void;
+typedef G5<invariant X extends core::num*> = <T extends S* = dynamic, S extends X* = dynamic>() →* void;
+typedef G6<invariant X extends core::num*> = <T extends X* = dynamic, S extends T* = dynamic>() →* void;
 typedef H1 = (<T extends core::Object* = dynamic>() →* void) →* void;
 typedef H2 = (<T extends core::num* = dynamic>() →* void) →* void;
 typedef H3 = (<T extends core::Object* = dynamic, S extends core::Object* = dynamic>() →* void) →* void;
diff --git a/pkg/front_end/testcases/general/generic_function_typedef.dart.weak.outline.expect b/pkg/front_end/testcases/general/generic_function_typedef.dart.weak.outline.expect
index 338c05f..cb01afe 100644
--- a/pkg/front_end/testcases/general/generic_function_typedef.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/generic_function_typedef.dart.weak.outline.expect
@@ -3,11 +3,11 @@
 import "dart:core" as core;
 
 typedef E1<unrelated T extends core::Object* = dynamic> = () →* void;
-typedef E2<unrelated T extends core::num* = core::num*> = () →* void;
+typedef E2<unrelated T extends core::num*> = () →* void;
 typedef E3<unrelated T extends core::Object* = dynamic, unrelated S extends core::Object* = dynamic> = () →* void;
-typedef E4<unrelated T extends core::num* = core::num*, unrelated S extends core::num* = core::num*> = () →* void;
-typedef E5<unrelated T extends S* = core::num*, unrelated S extends core::num* = core::num*> = () →* void;
-typedef E6<unrelated T extends core::num* = core::num*, unrelated S extends T* = core::num*> = () →* void;
+typedef E4<unrelated T extends core::num*, unrelated S extends core::num*> = () →* void;
+typedef E5<unrelated T extends S* = core::num*, unrelated S extends core::num*> = () →* void;
+typedef E6<unrelated T extends core::num*, unrelated S extends T* = core::num*> = () →* void;
 typedef F1 = <T extends core::Object* = dynamic>() →* void;
 typedef F2 = <T extends core::num* = dynamic>() →* void;
 typedef F3 = <T extends core::Object* = dynamic, S extends core::Object* = dynamic>() →* void;
@@ -15,11 +15,11 @@
 typedef F5 = <T extends S* = dynamic, S extends core::num* = dynamic>() →* void;
 typedef F6 = <T extends core::num* = dynamic, S extends T* = dynamic>() →* void;
 typedef G1<invariant X extends core::Object* = dynamic> = <T extends X* = dynamic>() →* void;
-typedef G2<invariant X extends core::num* = core::num*> = <T extends X* = dynamic>() →* void;
+typedef G2<invariant X extends core::num*> = <T extends X* = dynamic>() →* void;
 typedef G3<invariant X extends core::Object* = dynamic, invariant Y extends core::Object* = dynamic> = <T extends X* = dynamic, S extends Y* = dynamic>() →* void;
-typedef G4<invariant X extends core::num* = core::num*, invariant Y extends core::num* = core::num*> = <T extends X* = dynamic, S extends Y* = dynamic>() →* void;
-typedef G5<invariant X extends core::num* = core::num*> = <T extends S* = dynamic, S extends X* = dynamic>() →* void;
-typedef G6<invariant X extends core::num* = core::num*> = <T extends X* = dynamic, S extends T* = dynamic>() →* void;
+typedef G4<invariant X extends core::num*, invariant Y extends core::num*> = <T extends X* = dynamic, S extends Y* = dynamic>() →* void;
+typedef G5<invariant X extends core::num*> = <T extends S* = dynamic, S extends X* = dynamic>() →* void;
+typedef G6<invariant X extends core::num*> = <T extends X* = dynamic, S extends T* = dynamic>() →* void;
 typedef H1 = (<T extends core::Object* = dynamic>() →* void) →* void;
 typedef H2 = (<T extends core::num* = dynamic>() →* void) →* void;
 typedef H3 = (<T extends core::Object* = dynamic, S extends core::Object* = dynamic>() →* void) →* void;
diff --git a/pkg/front_end/testcases/general/generic_function_typedef.dart.weak.transformed.expect b/pkg/front_end/testcases/general/generic_function_typedef.dart.weak.transformed.expect
index adf2f0d..509ac9e 100644
--- a/pkg/front_end/testcases/general/generic_function_typedef.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/generic_function_typedef.dart.weak.transformed.expect
@@ -3,11 +3,11 @@
 import "dart:core" as core;
 
 typedef E1<unrelated T extends core::Object* = dynamic> = () →* void;
-typedef E2<unrelated T extends core::num* = core::num*> = () →* void;
+typedef E2<unrelated T extends core::num*> = () →* void;
 typedef E3<unrelated T extends core::Object* = dynamic, unrelated S extends core::Object* = dynamic> = () →* void;
-typedef E4<unrelated T extends core::num* = core::num*, unrelated S extends core::num* = core::num*> = () →* void;
-typedef E5<unrelated T extends S* = core::num*, unrelated S extends core::num* = core::num*> = () →* void;
-typedef E6<unrelated T extends core::num* = core::num*, unrelated S extends T* = core::num*> = () →* void;
+typedef E4<unrelated T extends core::num*, unrelated S extends core::num*> = () →* void;
+typedef E5<unrelated T extends S* = core::num*, unrelated S extends core::num*> = () →* void;
+typedef E6<unrelated T extends core::num*, unrelated S extends T* = core::num*> = () →* void;
 typedef F1 = <T extends core::Object* = dynamic>() →* void;
 typedef F2 = <T extends core::num* = dynamic>() →* void;
 typedef F3 = <T extends core::Object* = dynamic, S extends core::Object* = dynamic>() →* void;
@@ -15,11 +15,11 @@
 typedef F5 = <T extends S* = dynamic, S extends core::num* = dynamic>() →* void;
 typedef F6 = <T extends core::num* = dynamic, S extends T* = dynamic>() →* void;
 typedef G1<invariant X extends core::Object* = dynamic> = <T extends X* = dynamic>() →* void;
-typedef G2<invariant X extends core::num* = core::num*> = <T extends X* = dynamic>() →* void;
+typedef G2<invariant X extends core::num*> = <T extends X* = dynamic>() →* void;
 typedef G3<invariant X extends core::Object* = dynamic, invariant Y extends core::Object* = dynamic> = <T extends X* = dynamic, S extends Y* = dynamic>() →* void;
-typedef G4<invariant X extends core::num* = core::num*, invariant Y extends core::num* = core::num*> = <T extends X* = dynamic, S extends Y* = dynamic>() →* void;
-typedef G5<invariant X extends core::num* = core::num*> = <T extends S* = dynamic, S extends X* = dynamic>() →* void;
-typedef G6<invariant X extends core::num* = core::num*> = <T extends X* = dynamic, S extends T* = dynamic>() →* void;
+typedef G4<invariant X extends core::num*, invariant Y extends core::num*> = <T extends X* = dynamic, S extends Y* = dynamic>() →* void;
+typedef G5<invariant X extends core::num*> = <T extends S* = dynamic, S extends X* = dynamic>() →* void;
+typedef G6<invariant X extends core::num*> = <T extends X* = dynamic, S extends T* = dynamic>() →* void;
 typedef H1 = (<T extends core::Object* = dynamic>() →* void) →* void;
 typedef H2 = (<T extends core::num* = dynamic>() →* void) →* void;
 typedef H3 = (<T extends core::Object* = dynamic, S extends core::Object* = dynamic>() →* void) →* void;
diff --git a/pkg/front_end/testcases/general/getter_vs_setter_type.dart.weak.expect b/pkg/front_end/testcases/general/getter_vs_setter_type.dart.weak.expect
index 9842a9b..5d0cc59 100644
--- a/pkg/front_end/testcases/general/getter_vs_setter_type.dart.weak.expect
+++ b/pkg/front_end/testcases/general/getter_vs_setter_type.dart.weak.expect
@@ -352,7 +352,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-extension Extension<T extends core::num* = core::num*, S extends T* = core::num*> on core::int* {
+extension Extension<T extends core::num*, S extends T* = core::num*> on core::int* {
   get property1 = self::Extension|get#property1;
   get property2a = self::Extension|get#property2a;
   get property2b = self::Extension|get#property2b;
@@ -378,36 +378,36 @@
   static set property8b = set self::Extension|property8b;
   static set property9 = set self::Extension|property9;
 }
-static method Extension|get#property1<T extends core::num* = core::num*, S extends self::Extension|get#property1::T* = core::num*>(lowered final core::int* #this) → core::int*
+static method Extension|get#property1<T extends core::num*, S extends self::Extension|get#property1::T* = core::num*>(lowered final core::int* #this) → core::int*
   return 0;
-static method Extension|set#property1<T extends core::num* = core::num*, S extends self::Extension|set#property1::T* = core::num*>(lowered final core::int* #this, core::int* i) → void {}
-static method Extension|get#property2a<T extends core::num* = core::num*, S extends self::Extension|get#property2a::T* = core::num*>(lowered final core::int* #this) → core::num*
+static method Extension|set#property1<T extends core::num*, S extends self::Extension|set#property1::T* = core::num*>(lowered final core::int* #this, core::int* i) → void {}
+static method Extension|get#property2a<T extends core::num*, S extends self::Extension|get#property2a::T* = core::num*>(lowered final core::int* #this) → core::num*
   return 0;
-static method Extension|set#property2a<T extends core::num* = core::num*, S extends self::Extension|set#property2a::T* = core::num*>(lowered final core::int* #this, core::int* i) → void {}
-static method Extension|get#property2b<T extends core::num* = core::num*, S extends self::Extension|get#property2b::T* = core::num*>(lowered final core::int* #this) → core::int*
+static method Extension|set#property2a<T extends core::num*, S extends self::Extension|set#property2a::T* = core::num*>(lowered final core::int* #this, core::int* i) → void {}
+static method Extension|get#property2b<T extends core::num*, S extends self::Extension|get#property2b::T* = core::num*>(lowered final core::int* #this) → core::int*
   return 0;
-static method Extension|set#property2b<T extends core::num* = core::num*, S extends self::Extension|set#property2b::T* = core::num*>(lowered final core::int* #this, core::num* i) → void {}
-static method Extension|get#property3<T extends core::num* = core::num*, S extends self::Extension|get#property3::T* = core::num*>(lowered final core::int* #this) → core::String*
+static method Extension|set#property2b<T extends core::num*, S extends self::Extension|set#property2b::T* = core::num*>(lowered final core::int* #this, core::num* i) → void {}
+static method Extension|get#property3<T extends core::num*, S extends self::Extension|get#property3::T* = core::num*>(lowered final core::int* #this) → core::String*
   return "";
-static method Extension|set#property3<T extends core::num* = core::num*, S extends self::Extension|set#property3::T* = core::num*>(lowered final core::int* #this, core::int* i) → void {}
-static method Extension|get#property4<T extends core::num* = core::num*, S extends self::Extension|get#property4::T* = core::num*>(lowered final core::int* #this) → self::Extension|get#property4::S*
+static method Extension|set#property3<T extends core::num*, S extends self::Extension|set#property3::T* = core::num*>(lowered final core::int* #this, core::int* i) → void {}
+static method Extension|get#property4<T extends core::num*, S extends self::Extension|get#property4::T* = core::num*>(lowered final core::int* #this) → self::Extension|get#property4::S*
   return let final Never* #t1 = invalid-expression "pkg/front_end/testcases/general/getter_vs_setter_type.dart:133:22: Error: A value of type 'int' can't be assigned to a variable of type 'S'.
   S get property4 => 0; // ok
                      ^" in 0 as{TypeError} Never;
-static method Extension|set#property4<T extends core::num* = core::num*, S extends self::Extension|set#property4::T* = core::num*>(lowered final core::int* #this, self::Extension|set#property4::S* i) → void {}
-static method Extension|get#property5a<T extends core::num* = core::num*, S extends self::Extension|get#property5a::T* = core::num*>(lowered final core::int* #this) → self::Extension|get#property5a::S*
+static method Extension|set#property4<T extends core::num*, S extends self::Extension|set#property4::T* = core::num*>(lowered final core::int* #this, self::Extension|set#property4::S* i) → void {}
+static method Extension|get#property5a<T extends core::num*, S extends self::Extension|get#property5a::T* = core::num*>(lowered final core::int* #this) → self::Extension|get#property5a::S*
   return let final Never* #t2 = invalid-expression "pkg/front_end/testcases/general/getter_vs_setter_type.dart:136:23: Error: A value of type 'int' can't be assigned to a variable of type 'S'.
   S get property5a => 0; // ok
                       ^" in 0 as{TypeError} Never;
-static method Extension|set#property5a<T extends core::num* = core::num*, S extends self::Extension|set#property5a::T* = core::num*>(lowered final core::int* #this, self::Extension|set#property5a::T* i) → void {}
-static method Extension|get#property5b<T extends core::num* = core::num*, S extends self::Extension|get#property5b::T* = core::num*>(lowered final core::int* #this) → self::Extension|get#property5b::T*
+static method Extension|set#property5a<T extends core::num*, S extends self::Extension|set#property5a::T* = core::num*>(lowered final core::int* #this, self::Extension|set#property5a::T* i) → void {}
+static method Extension|get#property5b<T extends core::num*, S extends self::Extension|get#property5b::T* = core::num*>(lowered final core::int* #this) → self::Extension|get#property5b::T*
   return let final Never* #t3 = invalid-expression "pkg/front_end/testcases/general/getter_vs_setter_type.dart:139:23: Error: A value of type 'int' can't be assigned to a variable of type 'T'.
   T get property5b => 0; // ok
                       ^" in 0 as{TypeError} Never;
-static method Extension|set#property5b<T extends core::num* = core::num*, S extends self::Extension|set#property5b::T* = core::num*>(lowered final core::int* #this, self::Extension|set#property5b::S* i) → void {}
-static method Extension|get#property6<T extends core::num* = core::num*, S extends self::Extension|get#property6::T* = core::num*>(lowered final core::int* #this) → core::String*
+static method Extension|set#property5b<T extends core::num*, S extends self::Extension|set#property5b::T* = core::num*>(lowered final core::int* #this, self::Extension|set#property5b::S* i) → void {}
+static method Extension|get#property6<T extends core::num*, S extends self::Extension|get#property6::T* = core::num*>(lowered final core::int* #this) → core::String*
   return "";
-static method Extension|set#property6<T extends core::num* = core::num*, S extends self::Extension|set#property6::T* = core::num*>(lowered final core::int* #this, self::Extension|set#property6::S* i) → void {}
+static method Extension|set#property6<T extends core::num*, S extends self::Extension|set#property6::T* = core::num*>(lowered final core::int* #this, self::Extension|set#property6::S* i) → void {}
 static get Extension|property7() → core::int*
   return 0;
 static set Extension|property7(core::int* value) → void {}
diff --git a/pkg/front_end/testcases/general/getter_vs_setter_type.dart.weak.outline.expect b/pkg/front_end/testcases/general/getter_vs_setter_type.dart.weak.outline.expect
index 597b9c0..a903f97 100644
--- a/pkg/front_end/testcases/general/getter_vs_setter_type.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/getter_vs_setter_type.dart.weak.outline.expect
@@ -335,7 +335,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-extension Extension<T extends core::num* = core::num*, S extends T* = core::num*> on core::int* {
+extension Extension<T extends core::num*, S extends T* = core::num*> on core::int* {
   get property1 = self::Extension|get#property1;
   get property2a = self::Extension|get#property2a;
   get property2b = self::Extension|get#property2b;
@@ -361,37 +361,37 @@
   static set property8b = set self::Extension|property8b;
   static set property9 = set self::Extension|property9;
 }
-static method Extension|get#property1<T extends core::num* = core::num*, S extends self::Extension|get#property1::T* = core::num*>(lowered final core::int* #this) → core::int*
+static method Extension|get#property1<T extends core::num*, S extends self::Extension|get#property1::T* = core::num*>(lowered final core::int* #this) → core::int*
   ;
-static method Extension|set#property1<T extends core::num* = core::num*, S extends self::Extension|set#property1::T* = core::num*>(lowered final core::int* #this, core::int* i) → void
+static method Extension|set#property1<T extends core::num*, S extends self::Extension|set#property1::T* = core::num*>(lowered final core::int* #this, core::int* i) → void
   ;
-static method Extension|get#property2a<T extends core::num* = core::num*, S extends self::Extension|get#property2a::T* = core::num*>(lowered final core::int* #this) → core::num*
+static method Extension|get#property2a<T extends core::num*, S extends self::Extension|get#property2a::T* = core::num*>(lowered final core::int* #this) → core::num*
   ;
-static method Extension|set#property2a<T extends core::num* = core::num*, S extends self::Extension|set#property2a::T* = core::num*>(lowered final core::int* #this, core::int* i) → void
+static method Extension|set#property2a<T extends core::num*, S extends self::Extension|set#property2a::T* = core::num*>(lowered final core::int* #this, core::int* i) → void
   ;
-static method Extension|get#property2b<T extends core::num* = core::num*, S extends self::Extension|get#property2b::T* = core::num*>(lowered final core::int* #this) → core::int*
+static method Extension|get#property2b<T extends core::num*, S extends self::Extension|get#property2b::T* = core::num*>(lowered final core::int* #this) → core::int*
   ;
-static method Extension|set#property2b<T extends core::num* = core::num*, S extends self::Extension|set#property2b::T* = core::num*>(lowered final core::int* #this, core::num* i) → void
+static method Extension|set#property2b<T extends core::num*, S extends self::Extension|set#property2b::T* = core::num*>(lowered final core::int* #this, core::num* i) → void
   ;
-static method Extension|get#property3<T extends core::num* = core::num*, S extends self::Extension|get#property3::T* = core::num*>(lowered final core::int* #this) → core::String*
+static method Extension|get#property3<T extends core::num*, S extends self::Extension|get#property3::T* = core::num*>(lowered final core::int* #this) → core::String*
   ;
-static method Extension|set#property3<T extends core::num* = core::num*, S extends self::Extension|set#property3::T* = core::num*>(lowered final core::int* #this, core::int* i) → void
+static method Extension|set#property3<T extends core::num*, S extends self::Extension|set#property3::T* = core::num*>(lowered final core::int* #this, core::int* i) → void
   ;
-static method Extension|get#property4<T extends core::num* = core::num*, S extends self::Extension|get#property4::T* = core::num*>(lowered final core::int* #this) → self::Extension|get#property4::S*
+static method Extension|get#property4<T extends core::num*, S extends self::Extension|get#property4::T* = core::num*>(lowered final core::int* #this) → self::Extension|get#property4::S*
   ;
-static method Extension|set#property4<T extends core::num* = core::num*, S extends self::Extension|set#property4::T* = core::num*>(lowered final core::int* #this, self::Extension|set#property4::S* i) → void
+static method Extension|set#property4<T extends core::num*, S extends self::Extension|set#property4::T* = core::num*>(lowered final core::int* #this, self::Extension|set#property4::S* i) → void
   ;
-static method Extension|get#property5a<T extends core::num* = core::num*, S extends self::Extension|get#property5a::T* = core::num*>(lowered final core::int* #this) → self::Extension|get#property5a::S*
+static method Extension|get#property5a<T extends core::num*, S extends self::Extension|get#property5a::T* = core::num*>(lowered final core::int* #this) → self::Extension|get#property5a::S*
   ;
-static method Extension|set#property5a<T extends core::num* = core::num*, S extends self::Extension|set#property5a::T* = core::num*>(lowered final core::int* #this, self::Extension|set#property5a::T* i) → void
+static method Extension|set#property5a<T extends core::num*, S extends self::Extension|set#property5a::T* = core::num*>(lowered final core::int* #this, self::Extension|set#property5a::T* i) → void
   ;
-static method Extension|get#property5b<T extends core::num* = core::num*, S extends self::Extension|get#property5b::T* = core::num*>(lowered final core::int* #this) → self::Extension|get#property5b::T*
+static method Extension|get#property5b<T extends core::num*, S extends self::Extension|get#property5b::T* = core::num*>(lowered final core::int* #this) → self::Extension|get#property5b::T*
   ;
-static method Extension|set#property5b<T extends core::num* = core::num*, S extends self::Extension|set#property5b::T* = core::num*>(lowered final core::int* #this, self::Extension|set#property5b::S* i) → void
+static method Extension|set#property5b<T extends core::num*, S extends self::Extension|set#property5b::T* = core::num*>(lowered final core::int* #this, self::Extension|set#property5b::S* i) → void
   ;
-static method Extension|get#property6<T extends core::num* = core::num*, S extends self::Extension|get#property6::T* = core::num*>(lowered final core::int* #this) → core::String*
+static method Extension|get#property6<T extends core::num*, S extends self::Extension|get#property6::T* = core::num*>(lowered final core::int* #this) → core::String*
   ;
-static method Extension|set#property6<T extends core::num* = core::num*, S extends self::Extension|set#property6::T* = core::num*>(lowered final core::int* #this, self::Extension|set#property6::S* i) → void
+static method Extension|set#property6<T extends core::num*, S extends self::Extension|set#property6::T* = core::num*>(lowered final core::int* #this, self::Extension|set#property6::S* i) → void
   ;
 static get Extension|property7() → core::int*
   ;
diff --git a/pkg/front_end/testcases/general/implicit_covariance.dart.weak.expect b/pkg/front_end/testcases/general/implicit_covariance.dart.weak.expect
index 8661180..a8b24bc 100644
--- a/pkg/front_end/testcases/general/implicit_covariance.dart.weak.expect
+++ b/pkg/front_end/testcases/general/implicit_covariance.dart.weak.expect
@@ -49,19 +49,19 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-abstract class _D&C&B<T extends core::num* = core::num*> = self::C with self::B<self::_D&C&B::T*> /*isAnonymousMixin*/  {
+abstract class _D&C&B<T extends core::num*> = self::C with self::B<self::_D&C&B::T*> /*isAnonymousMixin*/  {
   synthetic constructor •() → self::_D&C&B<self::_D&C&B::T*>*
     : super self::C::•()
     ;
   forwarding-stub method foo(generic-covariant-impl core::num* x) → dynamic
     return super.{self::C::foo}(x);
 }
-class D<T extends core::num* = core::num*> extends self::_D&C&B<self::D::T*> {
+class D<T extends core::num*> extends self::_D&C&B<self::D::T*> {
   synthetic constructor •() → self::D<self::D::T*>*
     : super self::_D&C&B::•()
     ;
 }
-class E<T extends core::num* = core::num*> = self::C with self::B<self::E::T*> {
+class E<T extends core::num*> = self::C with self::B<self::E::T*> {
   synthetic constructor •() → self::E<self::E::T*>*
     : super self::C::•()
     ;
diff --git a/pkg/front_end/testcases/general/implicit_covariance.dart.weak.outline.expect b/pkg/front_end/testcases/general/implicit_covariance.dart.weak.outline.expect
index 613c5f9..63349f7 100644
--- a/pkg/front_end/testcases/general/implicit_covariance.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/implicit_covariance.dart.weak.outline.expect
@@ -47,18 +47,18 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-abstract class _D&C&B<T extends core::num* = core::num*> = self::C with self::B<self::_D&C&B::T*> /*isAnonymousMixin*/  {
+abstract class _D&C&B<T extends core::num*> = self::C with self::B<self::_D&C&B::T*> /*isAnonymousMixin*/  {
   synthetic constructor •() → self::_D&C&B<self::_D&C&B::T*>*
     : super self::C::•()
     ;
   forwarding-stub method foo(generic-covariant-impl core::num* x) → dynamic
     return super.{self::C::foo}(x);
 }
-class D<T extends core::num* = core::num*> extends self::_D&C&B<self::D::T*> {
+class D<T extends core::num*> extends self::_D&C&B<self::D::T*> {
   synthetic constructor •() → self::D<self::D::T*>*
     ;
 }
-class E<T extends core::num* = core::num*> = self::C with self::B<self::E::T*> {
+class E<T extends core::num*> = self::C with self::B<self::E::T*> {
   synthetic constructor •() → self::E<self::E::T*>*
     : super self::C::•()
     ;
diff --git a/pkg/front_end/testcases/general/implicit_covariance.dart.weak.transformed.expect b/pkg/front_end/testcases/general/implicit_covariance.dart.weak.transformed.expect
index d2f5898..c1432a4 100644
--- a/pkg/front_end/testcases/general/implicit_covariance.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/implicit_covariance.dart.weak.transformed.expect
@@ -49,19 +49,19 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-abstract class _D&C&B<T extends core::num* = core::num*> extends self::C implements self::B<self::_D&C&B::T*> /*isAnonymousMixin,isEliminatedMixin*/  {
+abstract class _D&C&B<T extends core::num*> extends self::C implements self::B<self::_D&C&B::T*> /*isAnonymousMixin,isEliminatedMixin*/  {
   synthetic constructor •() → self::_D&C&B<self::_D&C&B::T*>*
     : super self::C::•()
     ;
   forwarding-stub method foo(generic-covariant-impl core::num* x) → dynamic
     return super.{self::C::foo}(x);
 }
-class D<T extends core::num* = core::num*> extends self::_D&C&B<self::D::T*> {
+class D<T extends core::num*> extends self::_D&C&B<self::D::T*> {
   synthetic constructor •() → self::D<self::D::T*>*
     : super self::_D&C&B::•()
     ;
 }
-class E<T extends core::num* = core::num*> extends self::C implements self::B<self::E::T*> /*isEliminatedMixin*/  {
+class E<T extends core::num*> extends self::C implements self::B<self::E::T*> /*isEliminatedMixin*/  {
   synthetic constructor •() → self::E<self::E::T*>*
     : super self::C::•()
     ;
diff --git a/pkg/front_end/testcases/general/issue38812.dart.weak.expect b/pkg/front_end/testcases/general/issue38812.dart.weak.expect
index 07ce423..1bcd793 100644
--- a/pkg/front_end/testcases/general/issue38812.dart.weak.expect
+++ b/pkg/front_end/testcases/general/issue38812.dart.weak.expect
@@ -3,7 +3,7 @@
 import "dart:core" as core;
 
 typedef G<unrelated X extends core::Object* = dynamic> = () →* void;
-class A<X extends () →* void = () →* void, Y extends () →* void = () →* void> extends core::Object {
+class A<X extends () →* void, Y extends () →* void> extends core::Object {
   synthetic constructor •() → self::A<self::A::X*, self::A::Y*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/general/issue38812.dart.weak.outline.expect b/pkg/front_end/testcases/general/issue38812.dart.weak.outline.expect
index b09f203..d9a199c 100644
--- a/pkg/front_end/testcases/general/issue38812.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/issue38812.dart.weak.outline.expect
@@ -3,7 +3,7 @@
 import "dart:core" as core;
 
 typedef G<unrelated X extends core::Object* = dynamic> = () →* void;
-class A<X extends () →* void = () →* void, Y extends () →* void = () →* void> extends core::Object {
+class A<X extends () →* void, Y extends () →* void> extends core::Object {
   synthetic constructor •() → self::A<self::A::X*, self::A::Y*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/general/issue38812.dart.weak.transformed.expect b/pkg/front_end/testcases/general/issue38812.dart.weak.transformed.expect
index 07ce423..1bcd793 100644
--- a/pkg/front_end/testcases/general/issue38812.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/issue38812.dart.weak.transformed.expect
@@ -3,7 +3,7 @@
 import "dart:core" as core;
 
 typedef G<unrelated X extends core::Object* = dynamic> = () →* void;
-class A<X extends () →* void = () →* void, Y extends () →* void = () →* void> extends core::Object {
+class A<X extends () →* void, Y extends () →* void> extends core::Object {
   synthetic constructor •() → self::A<self::A::X*, self::A::Y*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/general/issue38943.dart.weak.expect b/pkg/front_end/testcases/general/issue38943.dart.weak.expect
index c85022a..c723406 100644
--- a/pkg/front_end/testcases/general/issue38943.dart.weak.expect
+++ b/pkg/front_end/testcases/general/issue38943.dart.weak.expect
@@ -2,10 +2,10 @@
 import self as self;
 import "dart:core" as core;
 
-class D<X extends () →* void = () →* void> extends core::Object {
+class D<X extends () →* void> extends core::Object {
   constructor _() → self::D<self::D::X*>*
     : super core::Object::•() {}
-  static factory foo<X extends () →* void = () →* void>() → self::D<self::D::foo::X*>*
+  static factory foo<X extends () →* void>() → self::D<self::D::foo::X*>*
     return new self::D::_<self::D::foo::X*>();
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
diff --git a/pkg/front_end/testcases/general/issue38943.dart.weak.outline.expect b/pkg/front_end/testcases/general/issue38943.dart.weak.outline.expect
index 0c892f9..7c3fcaf 100644
--- a/pkg/front_end/testcases/general/issue38943.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/issue38943.dart.weak.outline.expect
@@ -2,10 +2,10 @@
 import self as self;
 import "dart:core" as core;
 
-class D<X extends () →* void = () →* void> extends core::Object {
+class D<X extends () →* void> extends core::Object {
   constructor _() → self::D<self::D::X*>*
     ;
-  static factory foo<X extends () →* void = () →* void>() → self::D<self::D::foo::X*>*
+  static factory foo<X extends () →* void>() → self::D<self::D::foo::X*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
diff --git a/pkg/front_end/testcases/general/issue38943.dart.weak.transformed.expect b/pkg/front_end/testcases/general/issue38943.dart.weak.transformed.expect
index c85022a..c723406 100644
--- a/pkg/front_end/testcases/general/issue38943.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/issue38943.dart.weak.transformed.expect
@@ -2,10 +2,10 @@
 import self as self;
 import "dart:core" as core;
 
-class D<X extends () →* void = () →* void> extends core::Object {
+class D<X extends () →* void> extends core::Object {
   constructor _() → self::D<self::D::X*>*
     : super core::Object::•() {}
-  static factory foo<X extends () →* void = () →* void>() → self::D<self::D::foo::X*>*
+  static factory foo<X extends () →* void>() → self::D<self::D::foo::X*>*
     return new self::D::_<self::D::foo::X*>();
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
diff --git a/pkg/front_end/testcases/general/issue39344.dart.weak.expect b/pkg/front_end/testcases/general/issue39344.dart.weak.expect
index 5fdc524a..07a4d30 100644
--- a/pkg/front_end/testcases/general/issue39344.dart.weak.expect
+++ b/pkg/front_end/testcases/general/issue39344.dart.weak.expect
@@ -37,7 +37,7 @@
     : super self::A::•()
     ;
 }
-class Class<T extends self::A* = self::A*> extends core::Object {
+class Class<T extends self::A*> extends core::Object {
   synthetic constructor •() → self::Class<self::Class::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/general/issue39344.dart.weak.outline.expect b/pkg/front_end/testcases/general/issue39344.dart.weak.outline.expect
index fbf21ce..03e1065 100644
--- a/pkg/front_end/testcases/general/issue39344.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/issue39344.dart.weak.outline.expect
@@ -20,7 +20,7 @@
   synthetic constructor •() → self::B*
     ;
 }
-class Class<T extends self::A* = self::A*> extends core::Object {
+class Class<T extends self::A*> extends core::Object {
   synthetic constructor •() → self::Class<self::Class::T*>*
     ;
   method method1a(generic-covariant-impl self::Class::T* t) → void
diff --git a/pkg/front_end/testcases/general/issue39344.dart.weak.transformed.expect b/pkg/front_end/testcases/general/issue39344.dart.weak.transformed.expect
index ce3f707..7fe41a0 100644
--- a/pkg/front_end/testcases/general/issue39344.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/issue39344.dart.weak.transformed.expect
@@ -37,7 +37,7 @@
     : super self::A::•()
     ;
 }
-class Class<T extends self::A* = self::A*> extends core::Object {
+class Class<T extends self::A*> extends core::Object {
   synthetic constructor •() → self::Class<self::Class::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/general/issue43721.dart.weak.expect b/pkg/front_end/testcases/general/issue43721.dart.weak.expect
index c204fd6..4ca7943 100644
--- a/pkg/front_end/testcases/general/issue43721.dart.weak.expect
+++ b/pkg/front_end/testcases/general/issue43721.dart.weak.expect
@@ -15,8 +15,8 @@
 
 import "dart:async";
 
-static method ok<T extends FutureOr<core::num*>* = FutureOr<core::num*>*>(self::ok::T* t) → dynamic {}
-static method error<T extends FutureOr<core::int*>* = FutureOr<core::int*>*>(self::error::T* t) → dynamic {}
+static method ok<T extends FutureOr<core::num*>*>(self::ok::T* t) → dynamic {}
+static method error<T extends FutureOr<core::int*>*>(self::error::T* t) → dynamic {}
 static method bar(core::bool* condition) → dynamic {
   FutureOr<core::int*>* x = null;
   core::num* n = 1;
diff --git a/pkg/front_end/testcases/general/issue43721.dart.weak.outline.expect b/pkg/front_end/testcases/general/issue43721.dart.weak.outline.expect
index 84a6f86..710bffc 100644
--- a/pkg/front_end/testcases/general/issue43721.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/issue43721.dart.weak.outline.expect
@@ -4,9 +4,9 @@
 
 import "dart:async";
 
-static method ok<T extends FutureOr<core::num*>* = FutureOr<core::num*>*>(self::ok::T* t) → dynamic
+static method ok<T extends FutureOr<core::num*>*>(self::ok::T* t) → dynamic
   ;
-static method error<T extends FutureOr<core::int*>* = FutureOr<core::int*>*>(self::error::T* t) → dynamic
+static method error<T extends FutureOr<core::int*>*>(self::error::T* t) → dynamic
   ;
 static method bar(core::bool* condition) → dynamic
   ;
diff --git a/pkg/front_end/testcases/general/issue43721.dart.weak.transformed.expect b/pkg/front_end/testcases/general/issue43721.dart.weak.transformed.expect
index c204fd6..4ca7943 100644
--- a/pkg/front_end/testcases/general/issue43721.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/issue43721.dart.weak.transformed.expect
@@ -15,8 +15,8 @@
 
 import "dart:async";
 
-static method ok<T extends FutureOr<core::num*>* = FutureOr<core::num*>*>(self::ok::T* t) → dynamic {}
-static method error<T extends FutureOr<core::int*>* = FutureOr<core::int*>*>(self::error::T* t) → dynamic {}
+static method ok<T extends FutureOr<core::num*>*>(self::ok::T* t) → dynamic {}
+static method error<T extends FutureOr<core::int*>*>(self::error::T* t) → dynamic {}
 static method bar(core::bool* condition) → dynamic {
   FutureOr<core::int*>* x = null;
   core::num* n = 1;
diff --git a/pkg/front_end/testcases/general/issue44476.dart.weak.expect b/pkg/front_end/testcases/general/issue44476.dart.weak.expect
index 136f9b1..645587c 100644
--- a/pkg/front_end/testcases/general/issue44476.dart.weak.expect
+++ b/pkg/front_end/testcases/general/issue44476.dart.weak.expect
@@ -61,7 +61,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<X extends core::int* = core::int*> extends core::Object {
+class A<X extends core::int*> extends core::Object {
   synthetic constructor •() → self::A<self::A::X*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/general/issue44476.dart.weak.outline.expect b/pkg/front_end/testcases/general/issue44476.dart.weak.outline.expect
index 7f40fcf..2131965 100644
--- a/pkg/front_end/testcases/general/issue44476.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/issue44476.dart.weak.outline.expect
@@ -13,7 +13,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<X extends core::int* = core::int*> extends core::Object {
+class A<X extends core::int*> extends core::Object {
   synthetic constructor •() → self::A<self::A::X*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/general/issue44476.dart.weak.transformed.expect b/pkg/front_end/testcases/general/issue44476.dart.weak.transformed.expect
index 136f9b1..645587c 100644
--- a/pkg/front_end/testcases/general/issue44476.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/issue44476.dart.weak.transformed.expect
@@ -61,7 +61,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<X extends core::int* = core::int*> extends core::Object {
+class A<X extends core::int*> extends core::Object {
   synthetic constructor •() → self::A<self::A::X*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/general/issue45330.dart.weak.expect b/pkg/front_end/testcases/general/issue45330.dart.weak.expect
index c315320..22c456a 100644
--- a/pkg/front_end/testcases/general/issue45330.dart.weak.expect
+++ b/pkg/front_end/testcases/general/issue45330.dart.weak.expect
@@ -28,9 +28,9 @@
 part issue45330_lib.dart;
 static method genericMethod<T extends core::Object? = dynamic>() → void {}
 static method testInMain() → dynamic {
-  self::genericMethod<<T extends invalid-type = invalid-type>() → void>();
+  self::genericMethod<<T extends invalid-type>() → void>();
 }
 static method main() → dynamic {}
 static method /* from org-dartlang-testcase:///issue45330_lib.dart */ testInPart() → dynamic {
-  self::genericMethod<<T extends invalid-type = invalid-type>() → void>();
+  self::genericMethod<<T extends invalid-type>() → void>();
 }
diff --git a/pkg/front_end/testcases/general/issue45330.dart.weak.transformed.expect b/pkg/front_end/testcases/general/issue45330.dart.weak.transformed.expect
index c315320..22c456a 100644
--- a/pkg/front_end/testcases/general/issue45330.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/issue45330.dart.weak.transformed.expect
@@ -28,9 +28,9 @@
 part issue45330_lib.dart;
 static method genericMethod<T extends core::Object? = dynamic>() → void {}
 static method testInMain() → dynamic {
-  self::genericMethod<<T extends invalid-type = invalid-type>() → void>();
+  self::genericMethod<<T extends invalid-type>() → void>();
 }
 static method main() → dynamic {}
 static method /* from org-dartlang-testcase:///issue45330_lib.dart */ testInPart() → dynamic {
-  self::genericMethod<<T extends invalid-type = invalid-type>() → void>();
+  self::genericMethod<<T extends invalid-type>() → void>();
 }
diff --git a/pkg/front_end/testcases/general/issue45660.dart.weak.expect b/pkg/front_end/testcases/general/issue45660.dart.weak.expect
index cd197e9..f65680e 100644
--- a/pkg/front_end/testcases/general/issue45660.dart.weak.expect
+++ b/pkg/front_end/testcases/general/issue45660.dart.weak.expect
@@ -10,7 +10,7 @@
 import self as self;
 import "dart:core" as core;
 
-static field <T extends core::num* = dynamic>(T*) →* T* extendsNumReturnArg = <S extends core::num* = core::num*>(S* s) → S* => s;
+static field <T extends core::num* = dynamic>(T*) →* T* extendsNumReturnArg = <S extends core::num*>(S* s) → S* => s;
 static method functionInvocations() → dynamic {
   self::extendsNumReturnArg.call<Null>(null);
   self::extendsNumReturnArg.call<core::String*>("");
diff --git a/pkg/front_end/testcases/general/issue45660.dart.weak.transformed.expect b/pkg/front_end/testcases/general/issue45660.dart.weak.transformed.expect
index cd197e9..f65680e 100644
--- a/pkg/front_end/testcases/general/issue45660.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/issue45660.dart.weak.transformed.expect
@@ -10,7 +10,7 @@
 import self as self;
 import "dart:core" as core;
 
-static field <T extends core::num* = dynamic>(T*) →* T* extendsNumReturnArg = <S extends core::num* = core::num*>(S* s) → S* => s;
+static field <T extends core::num* = dynamic>(T*) →* T* extendsNumReturnArg = <S extends core::num*>(S* s) → S* => s;
 static method functionInvocations() → dynamic {
   self::extendsNumReturnArg.call<Null>(null);
   self::extendsNumReturnArg.call<core::String*>("");
diff --git a/pkg/front_end/testcases/general/mixin_inherited_setter_for_mixed_in_field.dart.weak.expect b/pkg/front_end/testcases/general/mixin_inherited_setter_for_mixed_in_field.dart.weak.expect
index 5465909..fce001a 100644
--- a/pkg/front_end/testcases/general/mixin_inherited_setter_for_mixed_in_field.dart.weak.expect
+++ b/pkg/front_end/testcases/general/mixin_inherited_setter_for_mixed_in_field.dart.weak.expect
@@ -17,7 +17,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class C<T extends self::A* = self::A*> extends core::Object {
+class C<T extends self::A*> extends core::Object {
   generic-covariant-impl field self::C::T* _field = null;
   synthetic constructor •() → self::C<self::C::T*>*
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/general/mixin_inherited_setter_for_mixed_in_field.dart.weak.outline.expect b/pkg/front_end/testcases/general/mixin_inherited_setter_for_mixed_in_field.dart.weak.outline.expect
index 4366b2f..8b4326c 100644
--- a/pkg/front_end/testcases/general/mixin_inherited_setter_for_mixed_in_field.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/mixin_inherited_setter_for_mixed_in_field.dart.weak.outline.expect
@@ -16,7 +16,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class C<T extends self::A* = self::A*> extends core::Object {
+class C<T extends self::A*> extends core::Object {
   generic-covariant-impl field self::C::T* _field;
   synthetic constructor •() → self::C<self::C::T*>*
     ;
diff --git a/pkg/front_end/testcases/general/mixin_inherited_setter_for_mixed_in_field.dart.weak.transformed.expect b/pkg/front_end/testcases/general/mixin_inherited_setter_for_mixed_in_field.dart.weak.transformed.expect
index 9828c0d..cd6518b 100644
--- a/pkg/front_end/testcases/general/mixin_inherited_setter_for_mixed_in_field.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/mixin_inherited_setter_for_mixed_in_field.dart.weak.transformed.expect
@@ -17,7 +17,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class C<T extends self::A* = self::A*> extends core::Object {
+class C<T extends self::A*> extends core::Object {
   generic-covariant-impl field self::C::T* _field = null;
   synthetic constructor •() → self::C<self::C::T*>*
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/general/nested_variance.dart.weak.expect b/pkg/front_end/testcases/general/nested_variance.dart.weak.expect
index e1dd3c7..ab01f23 100644
--- a/pkg/front_end/testcases/general/nested_variance.dart.weak.expect
+++ b/pkg/front_end/testcases/general/nested_variance.dart.weak.expect
@@ -6,9 +6,9 @@
 typedef Fcov<X extends core::Object* = dynamic> = () →* X*;
 typedef Fcon<contravariant X extends core::Object* = dynamic> = (X*) →* dynamic;
 typedef Finv<invariant X extends core::Object* = dynamic> = (X*) →* X*;
-typedef FcovBound<X extends core::num* = core::num*> = () →* X*;
-typedef FconBound<contravariant X extends core::num* = core::num*> = (X*) →* dynamic;
-typedef FinvBound<invariant X extends core::num* = core::num*> = (X*) →* X*;
+typedef FcovBound<X extends core::num*> = () →* X*;
+typedef FconBound<contravariant X extends core::num*> = (X*) →* dynamic;
+typedef FinvBound<invariant X extends core::num*> = (X*) →* X*;
 typedef FcovCyclicBound<X extends self::A<X*>* = self::A<dynamic>*> = () →* X*;
 typedef FconCyclicBound<contravariant X extends self::A<X*>* = self::A<Null>*> = (X*) →* dynamic;
 typedef FinvCyclicBound<invariant X extends self::A<X*>* = self::A<dynamic>*> = (X*) →* X*;
@@ -60,7 +60,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class AcovBound<X extends () →* self::AcovBound::Y* = () →* core::num*, Y extends core::num* = core::num*> extends core::Object {
+class AcovBound<X extends () →* self::AcovBound::Y* = () →* core::num*, Y extends core::num*> extends core::Object {
   synthetic constructor •() → self::AcovBound<self::AcovBound::X*, self::AcovBound::Y*>*
     : super core::Object::•()
     ;
@@ -75,7 +75,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class AconBound<X extends (self::AconBound::Y*) →* dynamic = (Null) →* dynamic, Y extends core::num* = core::num*> extends core::Object {
+class AconBound<X extends (self::AconBound::Y*) →* dynamic = (Null) →* dynamic, Y extends core::num*> extends core::Object {
   synthetic constructor •() → self::AconBound<self::AconBound::X*, self::AconBound::Y*>*
     : super core::Object::•()
     ;
@@ -90,7 +90,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class AinvBound<X extends (self::AinvBound::Y*) →* self::AinvBound::Y* = (core::num*) →* core::num*, Y extends core::num* = core::num*> extends core::Object {
+class AinvBound<X extends (self::AinvBound::Y*) →* self::AinvBound::Y* = (core::num*) →* core::num*, Y extends core::num*> extends core::Object {
   synthetic constructor •() → self::AinvBound<self::AinvBound::X*, self::AinvBound::Y*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/general/nested_variance.dart.weak.outline.expect b/pkg/front_end/testcases/general/nested_variance.dart.weak.outline.expect
index 1172b5e..c2384c9 100644
--- a/pkg/front_end/testcases/general/nested_variance.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/nested_variance.dart.weak.outline.expect
@@ -6,9 +6,9 @@
 typedef Fcov<X extends core::Object* = dynamic> = () →* X*;
 typedef Fcon<contravariant X extends core::Object* = dynamic> = (X*) →* dynamic;
 typedef Finv<invariant X extends core::Object* = dynamic> = (X*) →* X*;
-typedef FcovBound<X extends core::num* = core::num*> = () →* X*;
-typedef FconBound<contravariant X extends core::num* = core::num*> = (X*) →* dynamic;
-typedef FinvBound<invariant X extends core::num* = core::num*> = (X*) →* X*;
+typedef FcovBound<X extends core::num*> = () →* X*;
+typedef FconBound<contravariant X extends core::num*> = (X*) →* dynamic;
+typedef FinvBound<invariant X extends core::num*> = (X*) →* X*;
 typedef FcovCyclicBound<X extends self::A<X*>* = self::A<dynamic>*> = () →* X*;
 typedef FconCyclicBound<contravariant X extends self::A<X*>* = self::A<Null>*> = (X*) →* dynamic;
 typedef FinvCyclicBound<invariant X extends self::A<X*>* = self::A<dynamic>*> = (X*) →* X*;
@@ -57,7 +57,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class AcovBound<X extends () →* self::AcovBound::Y* = () →* core::num*, Y extends core::num* = core::num*> extends core::Object {
+class AcovBound<X extends () →* self::AcovBound::Y* = () →* core::num*, Y extends core::num*> extends core::Object {
   synthetic constructor •() → self::AcovBound<self::AcovBound::X*, self::AcovBound::Y*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
@@ -71,7 +71,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class AconBound<X extends (self::AconBound::Y*) →* dynamic = (Null) →* dynamic, Y extends core::num* = core::num*> extends core::Object {
+class AconBound<X extends (self::AconBound::Y*) →* dynamic = (Null) →* dynamic, Y extends core::num*> extends core::Object {
   synthetic constructor •() → self::AconBound<self::AconBound::X*, self::AconBound::Y*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
@@ -85,7 +85,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class AinvBound<X extends (self::AinvBound::Y*) →* self::AinvBound::Y* = (core::num*) →* core::num*, Y extends core::num* = core::num*> extends core::Object {
+class AinvBound<X extends (self::AinvBound::Y*) →* self::AinvBound::Y* = (core::num*) →* core::num*, Y extends core::num*> extends core::Object {
   synthetic constructor •() → self::AinvBound<self::AinvBound::X*, self::AinvBound::Y*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/general/nested_variance.dart.weak.transformed.expect b/pkg/front_end/testcases/general/nested_variance.dart.weak.transformed.expect
index e1dd3c7..ab01f23 100644
--- a/pkg/front_end/testcases/general/nested_variance.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/nested_variance.dart.weak.transformed.expect
@@ -6,9 +6,9 @@
 typedef Fcov<X extends core::Object* = dynamic> = () →* X*;
 typedef Fcon<contravariant X extends core::Object* = dynamic> = (X*) →* dynamic;
 typedef Finv<invariant X extends core::Object* = dynamic> = (X*) →* X*;
-typedef FcovBound<X extends core::num* = core::num*> = () →* X*;
-typedef FconBound<contravariant X extends core::num* = core::num*> = (X*) →* dynamic;
-typedef FinvBound<invariant X extends core::num* = core::num*> = (X*) →* X*;
+typedef FcovBound<X extends core::num*> = () →* X*;
+typedef FconBound<contravariant X extends core::num*> = (X*) →* dynamic;
+typedef FinvBound<invariant X extends core::num*> = (X*) →* X*;
 typedef FcovCyclicBound<X extends self::A<X*>* = self::A<dynamic>*> = () →* X*;
 typedef FconCyclicBound<contravariant X extends self::A<X*>* = self::A<Null>*> = (X*) →* dynamic;
 typedef FinvCyclicBound<invariant X extends self::A<X*>* = self::A<dynamic>*> = (X*) →* X*;
@@ -60,7 +60,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class AcovBound<X extends () →* self::AcovBound::Y* = () →* core::num*, Y extends core::num* = core::num*> extends core::Object {
+class AcovBound<X extends () →* self::AcovBound::Y* = () →* core::num*, Y extends core::num*> extends core::Object {
   synthetic constructor •() → self::AcovBound<self::AcovBound::X*, self::AcovBound::Y*>*
     : super core::Object::•()
     ;
@@ -75,7 +75,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class AconBound<X extends (self::AconBound::Y*) →* dynamic = (Null) →* dynamic, Y extends core::num* = core::num*> extends core::Object {
+class AconBound<X extends (self::AconBound::Y*) →* dynamic = (Null) →* dynamic, Y extends core::num*> extends core::Object {
   synthetic constructor •() → self::AconBound<self::AconBound::X*, self::AconBound::Y*>*
     : super core::Object::•()
     ;
@@ -90,7 +90,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class AinvBound<X extends (self::AinvBound::Y*) →* self::AinvBound::Y* = (core::num*) →* core::num*, Y extends core::num* = core::num*> extends core::Object {
+class AinvBound<X extends (self::AinvBound::Y*) →* self::AinvBound::Y* = (core::num*) →* core::num*, Y extends core::num*> extends core::Object {
   synthetic constructor •() → self::AinvBound<self::AinvBound::X*, self::AinvBound::Y*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/general/non_covariant_checks.dart.weak.expect b/pkg/front_end/testcases/general/non_covariant_checks.dart.weak.expect
index 39064e3..2f9cd4a 100644
--- a/pkg/front_end/testcases/general/non_covariant_checks.dart.weak.expect
+++ b/pkg/front_end/testcases/general/non_covariant_checks.dart.weak.expect
@@ -19,7 +19,7 @@
   generic-covariant-impl field <S extends self::C::T* = dynamic>(S*) →* S* field14;
   generic-covariant-impl field (<S extends self::C::T* = dynamic>() →* S*) →* void field15;
   constructor •(self::C::T* field1) → self::C<self::C::T*>*
-    : self::C::field1 = field1, self::C::field2 = () → self::C::T* => field1, self::C::field3 = (self::C::T* t) → Null {}, self::C::field4 = (self::C::T* t) → self::C::T* => t, self::C::field5 = () → () →* self::C::T* => () → self::C::T* => field1, self::C::field6 = (() →* self::C::T* f) → Null {}, self::C::field7 = (() →* self::C::T* f) → self::C::T* => field1, self::C::field8 = ((self::C::T*) →* void f) → Null {}, self::C::field9 = ((self::C::T*) →* void f) → self::C::T* => field1, self::C::field10 = ((self::C::T*) →* self::C::T* f) → Null {}, self::C::field11 = ((self::C::T*) →* self::C::T* f) → self::C::T* => field1, self::C::field12 = <S extends self::C::T* = self::C::T*>() → Null => null, self::C::field13 = <S extends self::C::T* = self::C::T*>(S* s) → Null {}, self::C::field14 = <S extends self::C::T* = self::C::T*>(S* s) → S* => s, self::C::field15 = (<S extends self::C::T* = self::C::T*>() →* S* f) → Null {}, super core::Object::•()
+    : self::C::field1 = field1, self::C::field2 = () → self::C::T* => field1, self::C::field3 = (self::C::T* t) → Null {}, self::C::field4 = (self::C::T* t) → self::C::T* => t, self::C::field5 = () → () →* self::C::T* => () → self::C::T* => field1, self::C::field6 = (() →* self::C::T* f) → Null {}, self::C::field7 = (() →* self::C::T* f) → self::C::T* => field1, self::C::field8 = ((self::C::T*) →* void f) → Null {}, self::C::field9 = ((self::C::T*) →* void f) → self::C::T* => field1, self::C::field10 = ((self::C::T*) →* self::C::T* f) → Null {}, self::C::field11 = ((self::C::T*) →* self::C::T* f) → self::C::T* => field1, self::C::field12 = <S extends self::C::T*>() → Null => null, self::C::field13 = <S extends self::C::T*>(S* s) → Null {}, self::C::field14 = <S extends self::C::T*>(S* s) → S* => s, self::C::field15 = (<S extends self::C::T*>() →* S* f) → Null {}, super core::Object::•()
     ;
   get getter1() → self::C::T*
     return this.{self::C::field1};
@@ -370,28 +370,28 @@
     core::print(e);
   }
   try {
-    c.{self::C::setter12} = <S extends core::num* = core::num*>() → Null => null;
+    c.{self::C::setter12} = <S extends core::num*>() → Null => null;
     throw "TypeError expected";
   }
   on core::TypeError* catch(final core::TypeError* e) {
     core::print(e);
   }
   try {
-    c.{self::C::setter13} = <S extends core::num* = core::num*>(S* s) → Null {};
+    c.{self::C::setter13} = <S extends core::num*>(S* s) → Null {};
     throw "TypeError expected";
   }
   on core::TypeError* catch(final core::TypeError* e) {
     core::print(e);
   }
   try {
-    c.{self::C::setter14} = <S extends core::num* = core::num*>(S* s) → S* => s;
+    c.{self::C::setter14} = <S extends core::num*>(S* s) → S* => s;
     throw "TypeError expected";
   }
   on core::TypeError* catch(final core::TypeError* e) {
     core::print(e);
   }
   try {
-    c.{self::C::setter15} = (<S extends core::num* = core::num*>() →* S* f) → Null {};
+    c.{self::C::setter15} = (<S extends core::num*>() →* S* f) → Null {};
     throw "TypeError expected";
   }
   on core::TypeError* catch(final core::TypeError* e) {
@@ -463,28 +463,28 @@
     core::print(e);
   }
   try {
-    c.{self::C::method12}(<S extends core::num* = core::num*>() → Null => null);
+    c.{self::C::method12}(<S extends core::num*>() → Null => null);
     throw "TypeError expected";
   }
   on core::TypeError* catch(final core::TypeError* e) {
     core::print(e);
   }
   try {
-    c.{self::C::method13}(<S extends core::num* = core::num*>(S* s) → Null {});
+    c.{self::C::method13}(<S extends core::num*>(S* s) → Null {});
     throw "TypeError expected";
   }
   on core::TypeError* catch(final core::TypeError* e) {
     core::print(e);
   }
   try {
-    c.{self::C::method14}(<S extends core::num* = core::num*>(S* s) → S* => s);
+    c.{self::C::method14}(<S extends core::num*>(S* s) → S* => s);
     throw "TypeError expected";
   }
   on core::TypeError* catch(final core::TypeError* e) {
     core::print(e);
   }
   try {
-    c.{self::C::method15}((<S extends core::num* = core::num*>() →* S* f) → Null {});
+    c.{self::C::method15}((<S extends core::num*>() →* S* f) → Null {});
     throw "TypeError expected";
   }
   on core::TypeError* catch(final core::TypeError* e) {
diff --git a/pkg/front_end/testcases/general/non_covariant_checks.dart.weak.transformed.expect b/pkg/front_end/testcases/general/non_covariant_checks.dart.weak.transformed.expect
index 39064e3..2f9cd4a 100644
--- a/pkg/front_end/testcases/general/non_covariant_checks.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/non_covariant_checks.dart.weak.transformed.expect
@@ -19,7 +19,7 @@
   generic-covariant-impl field <S extends self::C::T* = dynamic>(S*) →* S* field14;
   generic-covariant-impl field (<S extends self::C::T* = dynamic>() →* S*) →* void field15;
   constructor •(self::C::T* field1) → self::C<self::C::T*>*
-    : self::C::field1 = field1, self::C::field2 = () → self::C::T* => field1, self::C::field3 = (self::C::T* t) → Null {}, self::C::field4 = (self::C::T* t) → self::C::T* => t, self::C::field5 = () → () →* self::C::T* => () → self::C::T* => field1, self::C::field6 = (() →* self::C::T* f) → Null {}, self::C::field7 = (() →* self::C::T* f) → self::C::T* => field1, self::C::field8 = ((self::C::T*) →* void f) → Null {}, self::C::field9 = ((self::C::T*) →* void f) → self::C::T* => field1, self::C::field10 = ((self::C::T*) →* self::C::T* f) → Null {}, self::C::field11 = ((self::C::T*) →* self::C::T* f) → self::C::T* => field1, self::C::field12 = <S extends self::C::T* = self::C::T*>() → Null => null, self::C::field13 = <S extends self::C::T* = self::C::T*>(S* s) → Null {}, self::C::field14 = <S extends self::C::T* = self::C::T*>(S* s) → S* => s, self::C::field15 = (<S extends self::C::T* = self::C::T*>() →* S* f) → Null {}, super core::Object::•()
+    : self::C::field1 = field1, self::C::field2 = () → self::C::T* => field1, self::C::field3 = (self::C::T* t) → Null {}, self::C::field4 = (self::C::T* t) → self::C::T* => t, self::C::field5 = () → () →* self::C::T* => () → self::C::T* => field1, self::C::field6 = (() →* self::C::T* f) → Null {}, self::C::field7 = (() →* self::C::T* f) → self::C::T* => field1, self::C::field8 = ((self::C::T*) →* void f) → Null {}, self::C::field9 = ((self::C::T*) →* void f) → self::C::T* => field1, self::C::field10 = ((self::C::T*) →* self::C::T* f) → Null {}, self::C::field11 = ((self::C::T*) →* self::C::T* f) → self::C::T* => field1, self::C::field12 = <S extends self::C::T*>() → Null => null, self::C::field13 = <S extends self::C::T*>(S* s) → Null {}, self::C::field14 = <S extends self::C::T*>(S* s) → S* => s, self::C::field15 = (<S extends self::C::T*>() →* S* f) → Null {}, super core::Object::•()
     ;
   get getter1() → self::C::T*
     return this.{self::C::field1};
@@ -370,28 +370,28 @@
     core::print(e);
   }
   try {
-    c.{self::C::setter12} = <S extends core::num* = core::num*>() → Null => null;
+    c.{self::C::setter12} = <S extends core::num*>() → Null => null;
     throw "TypeError expected";
   }
   on core::TypeError* catch(final core::TypeError* e) {
     core::print(e);
   }
   try {
-    c.{self::C::setter13} = <S extends core::num* = core::num*>(S* s) → Null {};
+    c.{self::C::setter13} = <S extends core::num*>(S* s) → Null {};
     throw "TypeError expected";
   }
   on core::TypeError* catch(final core::TypeError* e) {
     core::print(e);
   }
   try {
-    c.{self::C::setter14} = <S extends core::num* = core::num*>(S* s) → S* => s;
+    c.{self::C::setter14} = <S extends core::num*>(S* s) → S* => s;
     throw "TypeError expected";
   }
   on core::TypeError* catch(final core::TypeError* e) {
     core::print(e);
   }
   try {
-    c.{self::C::setter15} = (<S extends core::num* = core::num*>() →* S* f) → Null {};
+    c.{self::C::setter15} = (<S extends core::num*>() →* S* f) → Null {};
     throw "TypeError expected";
   }
   on core::TypeError* catch(final core::TypeError* e) {
@@ -463,28 +463,28 @@
     core::print(e);
   }
   try {
-    c.{self::C::method12}(<S extends core::num* = core::num*>() → Null => null);
+    c.{self::C::method12}(<S extends core::num*>() → Null => null);
     throw "TypeError expected";
   }
   on core::TypeError* catch(final core::TypeError* e) {
     core::print(e);
   }
   try {
-    c.{self::C::method13}(<S extends core::num* = core::num*>(S* s) → Null {});
+    c.{self::C::method13}(<S extends core::num*>(S* s) → Null {});
     throw "TypeError expected";
   }
   on core::TypeError* catch(final core::TypeError* e) {
     core::print(e);
   }
   try {
-    c.{self::C::method14}(<S extends core::num* = core::num*>(S* s) → S* => s);
+    c.{self::C::method14}(<S extends core::num*>(S* s) → S* => s);
     throw "TypeError expected";
   }
   on core::TypeError* catch(final core::TypeError* e) {
     core::print(e);
   }
   try {
-    c.{self::C::method15}((<S extends core::num* = core::num*>() →* S* f) → Null {});
+    c.{self::C::method15}((<S extends core::num*>() →* S* f) → Null {});
     throw "TypeError expected";
   }
   on core::TypeError* catch(final core::TypeError* e) {
diff --git a/pkg/front_end/testcases/general/null_check_type_variable_type.dart.weak.expect b/pkg/front_end/testcases/general/null_check_type_variable_type.dart.weak.expect
index 6972fb1..02008c5 100644
--- a/pkg/front_end/testcases/general/null_check_type_variable_type.dart.weak.expect
+++ b/pkg/front_end/testcases/general/null_check_type_variable_type.dart.weak.expect
@@ -8,7 +8,7 @@
     : super core::Object::•()
     ;
 }
-class Class<E extends self::Element? = self::Element?> extends core::Object {
+class Class<E extends self::Element?> extends core::Object {
   generic-covariant-impl field self::Class::E? element;
   constructor •(self::Class::E? element) → self::Class<self::Class::E%>
     : self::Class::element = element, super core::Object::•()
diff --git a/pkg/front_end/testcases/general/null_check_type_variable_type.dart.weak.outline.expect b/pkg/front_end/testcases/general/null_check_type_variable_type.dart.weak.outline.expect
index 199055c..b66e3a9 100644
--- a/pkg/front_end/testcases/general/null_check_type_variable_type.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/null_check_type_variable_type.dart.weak.outline.expect
@@ -6,7 +6,7 @@
   synthetic constructor •() → self::Element
     ;
 }
-class Class<E extends self::Element? = self::Element?> extends core::Object {
+class Class<E extends self::Element?> extends core::Object {
   generic-covariant-impl field self::Class::E? element;
   constructor •(self::Class::E? element) → self::Class<self::Class::E%>
     ;
diff --git a/pkg/front_end/testcases/general/null_check_type_variable_type.dart.weak.transformed.expect b/pkg/front_end/testcases/general/null_check_type_variable_type.dart.weak.transformed.expect
index 6405a73..c5d8066 100644
--- a/pkg/front_end/testcases/general/null_check_type_variable_type.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/null_check_type_variable_type.dart.weak.transformed.expect
@@ -8,7 +8,7 @@
     : super core::Object::•()
     ;
 }
-class Class<E extends self::Element? = self::Element?> extends core::Object {
+class Class<E extends self::Element?> extends core::Object {
   generic-covariant-impl field self::Class::E? element;
   constructor •(self::Class::E? element) → self::Class<self::Class::E%>
     : self::Class::element = element, super core::Object::•()
diff --git a/pkg/front_end/testcases/general/redirecting_factory_typeargs_test.dart.weak.expect b/pkg/front_end/testcases/general/redirecting_factory_typeargs_test.dart.weak.expect
index 9ada94b..05a7185 100644
--- a/pkg/front_end/testcases/general/redirecting_factory_typeargs_test.dart.weak.expect
+++ b/pkg/front_end/testcases/general/redirecting_factory_typeargs_test.dart.weak.expect
@@ -40,7 +40,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class B<T extends self::X* = self::X*> extends self::A {
+class B<T extends self::X*> extends self::A {
   constructor •() → self::B<self::B::T*>*
     : super self::A::•()
     ;
diff --git a/pkg/front_end/testcases/general/redirecting_factory_typeargs_test.dart.weak.outline.expect b/pkg/front_end/testcases/general/redirecting_factory_typeargs_test.dart.weak.outline.expect
index fe27ae5..3cc1659 100644
--- a/pkg/front_end/testcases/general/redirecting_factory_typeargs_test.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/redirecting_factory_typeargs_test.dart.weak.outline.expect
@@ -37,7 +37,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class B<T extends self::X* = self::X*> extends self::A {
+class B<T extends self::X*> extends self::A {
   constructor •() → self::B<self::B::T*>*
     ;
 }
diff --git a/pkg/front_end/testcases/general/redirecting_factory_typeargs_test.dart.weak.transformed.expect b/pkg/front_end/testcases/general/redirecting_factory_typeargs_test.dart.weak.transformed.expect
index 35b0942..5fac4ba 100644
--- a/pkg/front_end/testcases/general/redirecting_factory_typeargs_test.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/redirecting_factory_typeargs_test.dart.weak.transformed.expect
@@ -40,7 +40,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class B<T extends self::X* = self::X*> extends self::A {
+class B<T extends self::X*> extends self::A {
   constructor •() → self::B<self::B::T*>*
     : super self::A::•()
     ;
diff --git a/pkg/front_end/testcases/general/redirecting_initializer_arguments_assignable_test.dart.weak.expect b/pkg/front_end/testcases/general/redirecting_initializer_arguments_assignable_test.dart.weak.expect
index 0afec65..6324f0a 100644
--- a/pkg/front_end/testcases/general/redirecting_initializer_arguments_assignable_test.dart.weak.expect
+++ b/pkg/front_end/testcases/general/redirecting_initializer_arguments_assignable_test.dart.weak.expect
@@ -17,7 +17,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Foo<T extends self::X* = self::X*> extends core::Object {
+class Foo<T extends self::X*> extends core::Object {
   generic-covariant-impl field self::Foo::T* x;
   constructor fromX(self::X* _init) → self::Foo<self::Foo::T*>*
     : this self::Foo::_internal(x: _init as{TypeError} self::Foo::T*)
diff --git a/pkg/front_end/testcases/general/redirecting_initializer_arguments_assignable_test.dart.weak.outline.expect b/pkg/front_end/testcases/general/redirecting_initializer_arguments_assignable_test.dart.weak.outline.expect
index 6210541..b816f4d 100644
--- a/pkg/front_end/testcases/general/redirecting_initializer_arguments_assignable_test.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/redirecting_initializer_arguments_assignable_test.dart.weak.outline.expect
@@ -16,7 +16,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Foo<T extends self::X* = self::X*> extends core::Object {
+class Foo<T extends self::X*> extends core::Object {
   generic-covariant-impl field self::Foo::T* x;
   constructor fromX(self::X* _init) → self::Foo<self::Foo::T*>*
     ;
diff --git a/pkg/front_end/testcases/general/redirecting_initializer_arguments_assignable_test.dart.weak.transformed.expect b/pkg/front_end/testcases/general/redirecting_initializer_arguments_assignable_test.dart.weak.transformed.expect
index 0afec65..6324f0a 100644
--- a/pkg/front_end/testcases/general/redirecting_initializer_arguments_assignable_test.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/redirecting_initializer_arguments_assignable_test.dart.weak.transformed.expect
@@ -17,7 +17,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Foo<T extends self::X* = self::X*> extends core::Object {
+class Foo<T extends self::X*> extends core::Object {
   generic-covariant-impl field self::Foo::T* x;
   constructor fromX(self::X* _init) → self::Foo<self::Foo::T*>*
     : this self::Foo::_internal(x: _init as{TypeError} self::Foo::T*)
diff --git a/pkg/front_end/testcases/general/top_level_variance_test.dart.weak.expect b/pkg/front_end/testcases/general/top_level_variance_test.dart.weak.expect
index b21e661..c61d2e4 100644
--- a/pkg/front_end/testcases/general/top_level_variance_test.dart.weak.expect
+++ b/pkg/front_end/testcases/general/top_level_variance_test.dart.weak.expect
@@ -6,9 +6,9 @@
 typedef Fcov<X extends core::Object* = dynamic> = () →* X*;
 typedef Fcon<contravariant X extends core::Object* = dynamic> = (X*) →* dynamic;
 typedef Finv<invariant X extends core::Object* = dynamic> = (X*) →* X*;
-typedef FcovBound<X extends core::num* = core::num*> = () →* X*;
-typedef FconBound<contravariant X extends core::num* = core::num*> = (X*) →* dynamic;
-typedef FinvBound<invariant X extends core::num* = core::num*> = (X*) →* X*;
+typedef FcovBound<X extends core::num*> = () →* X*;
+typedef FconBound<contravariant X extends core::num*> = (X*) →* dynamic;
+typedef FinvBound<invariant X extends core::num*> = (X*) →* X*;
 typedef FcovCyclicBound<X extends self::A<X*>* = self::A<dynamic>*> = () →* X*;
 typedef FconCyclicBound<contravariant X extends self::A<X*>* = self::A<Null>*> = (X*) →* dynamic;
 typedef FinvCyclicBound<invariant X extends self::A<X*>* = self::A<dynamic>*> = (X*) →* X*;
diff --git a/pkg/front_end/testcases/general/top_level_variance_test.dart.weak.outline.expect b/pkg/front_end/testcases/general/top_level_variance_test.dart.weak.outline.expect
index e79bd82..8e8cfa3 100644
--- a/pkg/front_end/testcases/general/top_level_variance_test.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/top_level_variance_test.dart.weak.outline.expect
@@ -6,9 +6,9 @@
 typedef Fcov<X extends core::Object* = dynamic> = () →* X*;
 typedef Fcon<contravariant X extends core::Object* = dynamic> = (X*) →* dynamic;
 typedef Finv<invariant X extends core::Object* = dynamic> = (X*) →* X*;
-typedef FcovBound<X extends core::num* = core::num*> = () →* X*;
-typedef FconBound<contravariant X extends core::num* = core::num*> = (X*) →* dynamic;
-typedef FinvBound<invariant X extends core::num* = core::num*> = (X*) →* X*;
+typedef FcovBound<X extends core::num*> = () →* X*;
+typedef FconBound<contravariant X extends core::num*> = (X*) →* dynamic;
+typedef FinvBound<invariant X extends core::num*> = (X*) →* X*;
 typedef FcovCyclicBound<X extends self::A<X*>* = self::A<dynamic>*> = () →* X*;
 typedef FconCyclicBound<contravariant X extends self::A<X*>* = self::A<Null>*> = (X*) →* dynamic;
 typedef FinvCyclicBound<invariant X extends self::A<X*>* = self::A<dynamic>*> = (X*) →* X*;
diff --git a/pkg/front_end/testcases/general/top_level_variance_test.dart.weak.transformed.expect b/pkg/front_end/testcases/general/top_level_variance_test.dart.weak.transformed.expect
index b21e661..c61d2e4 100644
--- a/pkg/front_end/testcases/general/top_level_variance_test.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/top_level_variance_test.dart.weak.transformed.expect
@@ -6,9 +6,9 @@
 typedef Fcov<X extends core::Object* = dynamic> = () →* X*;
 typedef Fcon<contravariant X extends core::Object* = dynamic> = (X*) →* dynamic;
 typedef Finv<invariant X extends core::Object* = dynamic> = (X*) →* X*;
-typedef FcovBound<X extends core::num* = core::num*> = () →* X*;
-typedef FconBound<contravariant X extends core::num* = core::num*> = (X*) →* dynamic;
-typedef FinvBound<invariant X extends core::num* = core::num*> = (X*) →* X*;
+typedef FcovBound<X extends core::num*> = () →* X*;
+typedef FconBound<contravariant X extends core::num*> = (X*) →* dynamic;
+typedef FinvBound<invariant X extends core::num*> = (X*) →* X*;
 typedef FcovCyclicBound<X extends self::A<X*>* = self::A<dynamic>*> = () →* X*;
 typedef FconCyclicBound<contravariant X extends self::A<X*>* = self::A<Null>*> = (X*) →* dynamic;
 typedef FinvCyclicBound<invariant X extends self::A<X*>* = self::A<dynamic>*> = (X*) →* X*;
diff --git a/pkg/front_end/testcases/general/type_variable_bound_access.dart.weak.expect b/pkg/front_end/testcases/general/type_variable_bound_access.dart.weak.expect
index 3700707..1e70230 100644
--- a/pkg/front_end/testcases/general/type_variable_bound_access.dart.weak.expect
+++ b/pkg/front_end/testcases/general/type_variable_bound_access.dart.weak.expect
@@ -10,7 +10,7 @@
 import self as self;
 import "dart:core" as core;
 
-class DynamicClass<T extends dynamic = dynamic, S extends self::DynamicClass::T* = dynamic> extends core::Object {
+class DynamicClass<T extends dynamic, S extends self::DynamicClass::T* = dynamic> extends core::Object {
   generic-covariant-impl field self::DynamicClass::T* field1;
   generic-covariant-impl field self::DynamicClass::T* field2;
   constructor •(self::DynamicClass::T* field1, self::DynamicClass::T* field2) → self::DynamicClass<self::DynamicClass::T*, self::DynamicClass::S*>*
@@ -29,7 +29,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class NumClass<T extends core::num* = core::num*, S extends self::NumClass::T* = core::num*> extends core::Object {
+class NumClass<T extends core::num*, S extends self::NumClass::T* = core::num*> extends core::Object {
   generic-covariant-impl field self::NumClass::T* field1;
   generic-covariant-impl field self::NumClass::S* field2;
   constructor •(self::NumClass::T* field1, self::NumClass::S* field2) → self::NumClass<self::NumClass::T*, self::NumClass::S*>*
@@ -53,7 +53,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Class<X5 extends self::Class::X4* = core::int*, X4 extends self::Class::X3* = core::int*, X3 extends self::Class::X2* = core::int*, X2 extends self::Class::X1* = core::int*, X1 extends self::Class::X0* = core::int*, X0 extends core::int* = core::int*> extends core::Object {
+class Class<X5 extends self::Class::X4* = core::int*, X4 extends self::Class::X3* = core::int*, X3 extends self::Class::X2* = core::int*, X2 extends self::Class::X1* = core::int*, X1 extends self::Class::X0* = core::int*, X0 extends core::int*> extends core::Object {
   generic-covariant-impl field self::Class::X0* field0 = null;
   generic-covariant-impl field self::Class::X1* field1 = null;
   generic-covariant-impl field self::Class::X2* field2 = null;
diff --git a/pkg/front_end/testcases/general/type_variable_bound_access.dart.weak.outline.expect b/pkg/front_end/testcases/general/type_variable_bound_access.dart.weak.outline.expect
index 9a25328..b02e918 100644
--- a/pkg/front_end/testcases/general/type_variable_bound_access.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/type_variable_bound_access.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class DynamicClass<T extends dynamic = dynamic, S extends self::DynamicClass::T* = dynamic> extends core::Object {
+class DynamicClass<T extends dynamic, S extends self::DynamicClass::T* = dynamic> extends core::Object {
   generic-covariant-impl field self::DynamicClass::T* field1;
   generic-covariant-impl field self::DynamicClass::T* field2;
   constructor •(self::DynamicClass::T* field1, self::DynamicClass::T* field2) → self::DynamicClass<self::DynamicClass::T*, self::DynamicClass::S*>*
@@ -20,7 +20,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class NumClass<T extends core::num* = core::num*, S extends self::NumClass::T* = core::num*> extends core::Object {
+class NumClass<T extends core::num*, S extends self::NumClass::T* = core::num*> extends core::Object {
   generic-covariant-impl field self::NumClass::T* field1;
   generic-covariant-impl field self::NumClass::S* field2;
   constructor •(self::NumClass::T* field1, self::NumClass::S* field2) → self::NumClass<self::NumClass::T*, self::NumClass::S*>*
@@ -40,7 +40,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Class<X5 extends self::Class::X4* = core::int*, X4 extends self::Class::X3* = core::int*, X3 extends self::Class::X2* = core::int*, X2 extends self::Class::X1* = core::int*, X1 extends self::Class::X0* = core::int*, X0 extends core::int* = core::int*> extends core::Object {
+class Class<X5 extends self::Class::X4* = core::int*, X4 extends self::Class::X3* = core::int*, X3 extends self::Class::X2* = core::int*, X2 extends self::Class::X1* = core::int*, X1 extends self::Class::X0* = core::int*, X0 extends core::int*> extends core::Object {
   generic-covariant-impl field self::Class::X0* field0;
   generic-covariant-impl field self::Class::X1* field1;
   generic-covariant-impl field self::Class::X2* field2;
diff --git a/pkg/front_end/testcases/general/type_variable_bound_access.dart.weak.transformed.expect b/pkg/front_end/testcases/general/type_variable_bound_access.dart.weak.transformed.expect
index dbc33c0..d9c7800 100644
--- a/pkg/front_end/testcases/general/type_variable_bound_access.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/type_variable_bound_access.dart.weak.transformed.expect
@@ -10,7 +10,7 @@
 import self as self;
 import "dart:core" as core;
 
-class DynamicClass<T extends dynamic = dynamic, S extends self::DynamicClass::T* = dynamic> extends core::Object {
+class DynamicClass<T extends dynamic, S extends self::DynamicClass::T* = dynamic> extends core::Object {
   generic-covariant-impl field self::DynamicClass::T* field1;
   generic-covariant-impl field self::DynamicClass::T* field2;
   constructor •(self::DynamicClass::T* field1, self::DynamicClass::T* field2) → self::DynamicClass<self::DynamicClass::T*, self::DynamicClass::S*>*
@@ -29,7 +29,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class NumClass<T extends core::num* = core::num*, S extends self::NumClass::T* = core::num*> extends core::Object {
+class NumClass<T extends core::num*, S extends self::NumClass::T* = core::num*> extends core::Object {
   generic-covariant-impl field self::NumClass::T* field1;
   generic-covariant-impl field self::NumClass::S* field2;
   constructor •(self::NumClass::T* field1, self::NumClass::S* field2) → self::NumClass<self::NumClass::T*, self::NumClass::S*>*
@@ -53,7 +53,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Class<X5 extends self::Class::X4* = core::int*, X4 extends self::Class::X3* = core::int*, X3 extends self::Class::X2* = core::int*, X2 extends self::Class::X1* = core::int*, X1 extends self::Class::X0* = core::int*, X0 extends core::int* = core::int*> extends core::Object {
+class Class<X5 extends self::Class::X4* = core::int*, X4 extends self::Class::X3* = core::int*, X3 extends self::Class::X2* = core::int*, X2 extends self::Class::X1* = core::int*, X1 extends self::Class::X0* = core::int*, X0 extends core::int*> extends core::Object {
   generic-covariant-impl field self::Class::X0* field0 = null;
   generic-covariant-impl field self::Class::X1* field1 = null;
   generic-covariant-impl field self::Class::X2* field2 = null;
diff --git a/pkg/front_end/testcases/general/unsound_promotion.dart.weak.expect b/pkg/front_end/testcases/general/unsound_promotion.dart.weak.expect
index 10cd814..bf4731f 100644
--- a/pkg/front_end/testcases/general/unsound_promotion.dart.weak.expect
+++ b/pkg/front_end/testcases/general/unsound_promotion.dart.weak.expect
@@ -50,7 +50,7 @@
     ;
 }
 static field core::List<self::A*>* list;
-static method g<T extends self::A* = self::A*>(self::g::T* t) → core::List<self::g::T*>* {
+static method g<T extends self::A*>(self::g::T* t) → core::List<self::g::T*>* {
   self::list = <self::g::T*>[];
   core::print(self::list.{core::Object::runtimeType});
   return self::list as{TypeError} core::List<self::g::T*>*;
diff --git a/pkg/front_end/testcases/general/unsound_promotion.dart.weak.outline.expect b/pkg/front_end/testcases/general/unsound_promotion.dart.weak.outline.expect
index 4d2b9c0..6b3902f 100644
--- a/pkg/front_end/testcases/general/unsound_promotion.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/unsound_promotion.dart.weak.outline.expect
@@ -35,7 +35,7 @@
     ;
 }
 static field core::List<self::A*>* list;
-static method g<T extends self::A* = self::A*>(self::g::T* t) → core::List<self::g::T*>*
+static method g<T extends self::A*>(self::g::T* t) → core::List<self::g::T*>*
   ;
 static method f<S extends core::Object* = dynamic>(self::f::S* s) → core::List<self::f::S*>*
   ;
diff --git a/pkg/front_end/testcases/general/vm_type_ops.dart.weak.expect b/pkg/front_end/testcases/general/vm_type_ops.dart.weak.expect
index f5999a8..2091c88 100644
--- a/pkg/front_end/testcases/general/vm_type_ops.dart.weak.expect
+++ b/pkg/front_end/testcases/general/vm_type_ops.dart.weak.expect
@@ -55,10 +55,10 @@
     return w as{TypeError,ForDynamic} core::Map<self::D::P*, self::D::Q*>*;
   }
 }
-class E<P extends core::String* = core::String*> extends core::Object {
-  static factory •<P extends core::String* = core::String*>() → self::E<self::E::•::P*>*
+class E<P extends core::String*> extends core::Object {
+  static factory •<P extends core::String*>() → self::E<self::E::•::P*>*
     return null;
-  method foo6<generic-covariant-impl T extends self::E::P* = self::E::P*, U extends core::List<self::E::foo6::T*>* = core::List<self::E::P*>*>(core::Map<self::E::foo6::T*, self::E::foo6::U*>* map) → void {}
+  method foo6<generic-covariant-impl T extends self::E::P*, U extends core::List<self::E::foo6::T*>* = core::List<self::E::P*>*>(core::Map<self::E::foo6::T*, self::E::foo6::U*>* map) → void {}
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
@@ -74,8 +74,8 @@
   synthetic constructor •() → self::F<self::F::T*>*
     : super core::Object::•()
     ;
-  abstract method foo7<generic-covariant-impl Q extends self::F::T* = self::F::T*>(self::F::foo7::Q* a, covariant core::num* b, generic-covariant-impl self::F::T* c) → void;
-  abstract method foo8<generic-covariant-impl Q extends self::F::T* = self::F::T*>(self::F::foo8::Q* a, covariant core::num* b, generic-covariant-impl self::F::T* c) → void;
+  abstract method foo7<generic-covariant-impl Q extends self::F::T*>(self::F::foo7::Q* a, covariant core::num* b, generic-covariant-impl self::F::T* c) → void;
+  abstract method foo8<generic-covariant-impl Q extends self::F::T*>(self::F::foo8::Q* a, covariant core::num* b, generic-covariant-impl self::F::T* c) → void;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
@@ -91,7 +91,7 @@
   synthetic constructor •() → self::G<self::G::T*>*
     : super core::Object::•()
     ;
-  method foo7<generic-covariant-impl Q extends self::G::T* = self::G::T*>(self::G::foo7::Q* a, core::int* b, generic-covariant-impl self::G::T* c) → void {}
+  method foo7<generic-covariant-impl Q extends self::G::T*>(self::G::foo7::Q* a, core::int* b, generic-covariant-impl self::G::T* c) → void {}
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
@@ -107,8 +107,8 @@
   synthetic constructor •() → self::H<self::H::T*>*
     : super self::G::•()
     ;
-  method foo8<generic-covariant-impl Q extends self::H::T* = self::H::T*>(self::H::foo8::Q* a, covariant core::int* b, generic-covariant-impl self::H::T* c) → void {}
-  forwarding-stub method foo7<generic-covariant-impl Q extends self::H::T* = self::H::T*>(self::H::foo7::Q* a, covariant core::num* b, generic-covariant-impl self::H::T* c) → void
+  method foo8<generic-covariant-impl Q extends self::H::T*>(self::H::foo8::Q* a, covariant core::int* b, generic-covariant-impl self::H::T* c) → void {}
+  forwarding-stub method foo7<generic-covariant-impl Q extends self::H::T*>(self::H::foo7::Q* a, covariant core::num* b, generic-covariant-impl self::H::T* c) → void
     return super.{self::G::foo7}<self::H::foo7::Q*>(a, b, c);
 }
 static field core::List<core::Iterable<dynamic>*>* globalVar;
diff --git a/pkg/front_end/testcases/general/vm_type_ops.dart.weak.outline.expect b/pkg/front_end/testcases/general/vm_type_ops.dart.weak.outline.expect
index c37c149..679e7c3 100644
--- a/pkg/front_end/testcases/general/vm_type_ops.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/vm_type_ops.dart.weak.outline.expect
@@ -35,10 +35,10 @@
   method foo4(dynamic w) → core::Map<self::D::P*, self::D::Q*>*
     ;
 }
-class E<P extends core::String* = core::String*> extends core::Object {
-  static factory •<P extends core::String* = core::String*>() → self::E<self::E::•::P*>*
+class E<P extends core::String*> extends core::Object {
+  static factory •<P extends core::String*>() → self::E<self::E::•::P*>*
     ;
-  method foo6<generic-covariant-impl T extends self::E::P* = self::E::P*, U extends core::List<self::E::foo6::T*>* = core::List<self::E::P*>*>(core::Map<self::E::foo6::T*, self::E::foo6::U*>* map) → void
+  method foo6<generic-covariant-impl T extends self::E::P*, U extends core::List<self::E::foo6::T*>* = core::List<self::E::P*>*>(core::Map<self::E::foo6::T*, self::E::foo6::U*>* map) → void
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -54,8 +54,8 @@
 abstract class F<T extends core::Object* = dynamic> extends core::Object {
   synthetic constructor •() → self::F<self::F::T*>*
     ;
-  abstract method foo7<generic-covariant-impl Q extends self::F::T* = self::F::T*>(self::F::foo7::Q* a, covariant core::num* b, generic-covariant-impl self::F::T* c) → void;
-  abstract method foo8<generic-covariant-impl Q extends self::F::T* = self::F::T*>(self::F::foo8::Q* a, covariant core::num* b, generic-covariant-impl self::F::T* c) → void;
+  abstract method foo7<generic-covariant-impl Q extends self::F::T*>(self::F::foo7::Q* a, covariant core::num* b, generic-covariant-impl self::F::T* c) → void;
+  abstract method foo8<generic-covariant-impl Q extends self::F::T*>(self::F::foo8::Q* a, covariant core::num* b, generic-covariant-impl self::F::T* c) → void;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
@@ -70,7 +70,7 @@
 class G<T extends core::Object* = dynamic> extends core::Object {
   synthetic constructor •() → self::G<self::G::T*>*
     ;
-  method foo7<generic-covariant-impl Q extends self::G::T* = self::G::T*>(self::G::foo7::Q* a, core::int* b, generic-covariant-impl self::G::T* c) → void
+  method foo7<generic-covariant-impl Q extends self::G::T*>(self::G::foo7::Q* a, core::int* b, generic-covariant-impl self::G::T* c) → void
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -86,9 +86,9 @@
 class H<T extends core::Object* = dynamic> extends self::G<self::H::T*> implements self::F<self::H::T*> {
   synthetic constructor •() → self::H<self::H::T*>*
     ;
-  method foo8<generic-covariant-impl Q extends self::H::T* = self::H::T*>(self::H::foo8::Q* a, covariant core::int* b, generic-covariant-impl self::H::T* c) → void
+  method foo8<generic-covariant-impl Q extends self::H::T*>(self::H::foo8::Q* a, covariant core::int* b, generic-covariant-impl self::H::T* c) → void
     ;
-  forwarding-stub method foo7<generic-covariant-impl Q extends self::H::T* = self::H::T*>(self::H::foo7::Q* a, covariant core::num* b, generic-covariant-impl self::H::T* c) → void
+  forwarding-stub method foo7<generic-covariant-impl Q extends self::H::T*>(self::H::foo7::Q* a, covariant core::num* b, generic-covariant-impl self::H::T* c) → void
     return super.{self::G::foo7}<self::H::foo7::Q*>(a, b, c);
 }
 static field core::List<core::Iterable<dynamic>*>* globalVar;
diff --git a/pkg/front_end/testcases/general/vm_type_ops.dart.weak.transformed.expect b/pkg/front_end/testcases/general/vm_type_ops.dart.weak.transformed.expect
index 63d1a23..ce44cfa 100644
--- a/pkg/front_end/testcases/general/vm_type_ops.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/vm_type_ops.dart.weak.transformed.expect
@@ -55,10 +55,10 @@
     return w as{TypeError,ForDynamic} core::Map<self::D::P*, self::D::Q*>*;
   }
 }
-class E<P extends core::String* = core::String*> extends core::Object {
-  static factory •<P extends core::String* = core::String*>() → self::E<self::E::•::P*>*
+class E<P extends core::String*> extends core::Object {
+  static factory •<P extends core::String*>() → self::E<self::E::•::P*>*
     return null;
-  method foo6<generic-covariant-impl T extends self::E::P* = self::E::P*, U extends core::List<self::E::foo6::T*>* = core::List<self::E::P*>*>(core::Map<self::E::foo6::T*, self::E::foo6::U*>* map) → void {}
+  method foo6<generic-covariant-impl T extends self::E::P*, U extends core::List<self::E::foo6::T*>* = core::List<self::E::P*>*>(core::Map<self::E::foo6::T*, self::E::foo6::U*>* map) → void {}
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
@@ -74,8 +74,8 @@
   synthetic constructor •() → self::F<self::F::T*>*
     : super core::Object::•()
     ;
-  abstract method foo7<generic-covariant-impl Q extends self::F::T* = self::F::T*>(self::F::foo7::Q* a, covariant core::num* b, generic-covariant-impl self::F::T* c) → void;
-  abstract method foo8<generic-covariant-impl Q extends self::F::T* = self::F::T*>(self::F::foo8::Q* a, covariant core::num* b, generic-covariant-impl self::F::T* c) → void;
+  abstract method foo7<generic-covariant-impl Q extends self::F::T*>(self::F::foo7::Q* a, covariant core::num* b, generic-covariant-impl self::F::T* c) → void;
+  abstract method foo8<generic-covariant-impl Q extends self::F::T*>(self::F::foo8::Q* a, covariant core::num* b, generic-covariant-impl self::F::T* c) → void;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
@@ -91,7 +91,7 @@
   synthetic constructor •() → self::G<self::G::T*>*
     : super core::Object::•()
     ;
-  method foo7<generic-covariant-impl Q extends self::G::T* = self::G::T*>(self::G::foo7::Q* a, core::int* b, generic-covariant-impl self::G::T* c) → void {}
+  method foo7<generic-covariant-impl Q extends self::G::T*>(self::G::foo7::Q* a, core::int* b, generic-covariant-impl self::G::T* c) → void {}
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
@@ -107,8 +107,8 @@
   synthetic constructor •() → self::H<self::H::T*>*
     : super self::G::•()
     ;
-  method foo8<generic-covariant-impl Q extends self::H::T* = self::H::T*>(self::H::foo8::Q* a, covariant core::int* b, generic-covariant-impl self::H::T* c) → void {}
-  forwarding-stub method foo7<generic-covariant-impl Q extends self::H::T* = self::H::T*>(self::H::foo7::Q* a, covariant core::num* b, generic-covariant-impl self::H::T* c) → void
+  method foo8<generic-covariant-impl Q extends self::H::T*>(self::H::foo8::Q* a, covariant core::int* b, generic-covariant-impl self::H::T* c) → void {}
+  forwarding-stub method foo7<generic-covariant-impl Q extends self::H::T*>(self::H::foo7::Q* a, covariant core::num* b, generic-covariant-impl self::H::T* c) → void
     return super.{self::G::foo7}<self::H::foo7::Q*>(a, b, c);
 }
 static field core::List<core::Iterable<dynamic>*>* globalVar;
diff --git a/pkg/front_end/testcases/general/well_boundness_checks_in_outline.dart.weak.expect b/pkg/front_end/testcases/general/well_boundness_checks_in_outline.dart.weak.expect
index 56d2323..a688b79 100644
--- a/pkg/front_end/testcases/general/well_boundness_checks_in_outline.dart.weak.expect
+++ b/pkg/front_end/testcases/general/well_boundness_checks_in_outline.dart.weak.expect
@@ -61,7 +61,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<X extends core::int* = core::int*> extends core::Object {
+class A<X extends core::int*> extends core::Object {
   synthetic constructor •() → self::A<self::A::X*>*
     : super core::Object::•()
     ;
@@ -93,7 +93,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-extension E<X extends self::A<core::num*>* = self::A<core::num*>*> on self::A<core::int*>* {
+extension E<X extends self::A<core::num*>*> on self::A<core::int*>* {
   static field fieldOfE = self::E|fieldOfE;
   method fooOfE = self::E|fooOfE;
   tearoff fooOfE = self::E|get#fooOfE;
@@ -103,14 +103,14 @@
   tearoff bazOfE = self::E|get#bazOfE;
 }
 static field self::A<core::num*>* E|fieldOfE;
-static method E|fooOfE<X extends self::A<core::num*>* = self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → self::A<core::num*>*
+static method E|fooOfE<X extends self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → self::A<core::num*>*
   return null;
-static method E|get#fooOfE<X extends self::A<core::num*>* = self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → () →* self::A<core::num*>*
+static method E|get#fooOfE<X extends self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → () →* self::A<core::num*>*
   return () → self::A<core::num*>* => self::E|fooOfE<self::E|get#fooOfE::X*>(#this);
-static method E|barOfE<X extends self::A<core::num*>* = self::A<core::num*>*>(lowered final self::A<core::int*>* #this, self::A<core::num*>* a) → void {}
-static method E|get#barOfE<X extends self::A<core::num*>* = self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → (self::A<core::num*>*) →* void
+static method E|barOfE<X extends self::A<core::num*>*>(lowered final self::A<core::int*>* #this, self::A<core::num*>* a) → void {}
+static method E|get#barOfE<X extends self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → (self::A<core::num*>*) →* void
   return (self::A<core::num*>* a) → void => self::E|barOfE<self::E|get#barOfE::X*>(#this, a);
-static method E|bazOfE<X extends self::A<core::num*>* = self::A<core::num*>*, Y extends self::A<core::num*>* = self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → void {}
-static method E|get#bazOfE<X extends self::A<core::num*>* = self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → <Y extends self::A<core::num*>* = self::A<core::num*>*>() →* void
-  return <Y extends self::A<core::num*>* = self::A<core::num*>*>() → void => self::E|bazOfE<self::E|get#bazOfE::X*, Y*>(#this);
+static method E|bazOfE<X extends self::A<core::num*>*, Y extends self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → void {}
+static method E|get#bazOfE<X extends self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → <Y extends self::A<core::num*>*>() →* void
+  return <Y extends self::A<core::num*>*>() → void => self::E|bazOfE<self::E|get#bazOfE::X*, Y*>(#this);
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/general/well_boundness_checks_in_outline.dart.weak.outline.expect b/pkg/front_end/testcases/general/well_boundness_checks_in_outline.dart.weak.outline.expect
index 82ff41e..f1bac31 100644
--- a/pkg/front_end/testcases/general/well_boundness_checks_in_outline.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/general/well_boundness_checks_in_outline.dart.weak.outline.expect
@@ -61,7 +61,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<X extends core::int* = core::int*> extends core::Object {
+class A<X extends core::int*> extends core::Object {
   synthetic constructor •() → self::A<self::A::X*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
@@ -91,7 +91,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-extension E<X extends self::A<core::num*>* = self::A<core::num*>*> on self::A<core::int*>* {
+extension E<X extends self::A<core::num*>*> on self::A<core::int*>* {
   static field fieldOfE = self::E|fieldOfE;
   method fooOfE = self::E|fooOfE;
   tearoff fooOfE = self::E|get#fooOfE;
@@ -101,17 +101,17 @@
   tearoff bazOfE = self::E|get#bazOfE;
 }
 static field self::A<core::num*>* E|fieldOfE;
-static method E|fooOfE<X extends self::A<core::num*>* = self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → self::A<core::num*>*
+static method E|fooOfE<X extends self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → self::A<core::num*>*
   ;
-static method E|get#fooOfE<X extends self::A<core::num*>* = self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → () →* self::A<core::num*>*
+static method E|get#fooOfE<X extends self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → () →* self::A<core::num*>*
   return () → self::A<core::num*>* => self::E|fooOfE<self::E|get#fooOfE::X*>(#this);
-static method E|barOfE<X extends self::A<core::num*>* = self::A<core::num*>*>(lowered final self::A<core::int*>* #this, self::A<core::num*>* a) → void
+static method E|barOfE<X extends self::A<core::num*>*>(lowered final self::A<core::int*>* #this, self::A<core::num*>* a) → void
   ;
-static method E|get#barOfE<X extends self::A<core::num*>* = self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → (self::A<core::num*>*) →* void
+static method E|get#barOfE<X extends self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → (self::A<core::num*>*) →* void
   return (self::A<core::num*>* a) → void => self::E|barOfE<self::E|get#barOfE::X*>(#this, a);
-static method E|bazOfE<X extends self::A<core::num*>* = self::A<core::num*>*, Y extends self::A<core::num*>* = self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → void
+static method E|bazOfE<X extends self::A<core::num*>*, Y extends self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → void
   ;
-static method E|get#bazOfE<X extends self::A<core::num*>* = self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → <Y extends self::A<core::num*>* = self::A<core::num*>*>() →* void
-  return <Y extends self::A<core::num*>* = self::A<core::num*>*>() → void => self::E|bazOfE<self::E|get#bazOfE::X*, Y*>(#this);
+static method E|get#bazOfE<X extends self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → <Y extends self::A<core::num*>*>() →* void
+  return <Y extends self::A<core::num*>*>() → void => self::E|bazOfE<self::E|get#bazOfE::X*, Y*>(#this);
 static method main() → dynamic
   ;
diff --git a/pkg/front_end/testcases/general/well_boundness_checks_in_outline.dart.weak.transformed.expect b/pkg/front_end/testcases/general/well_boundness_checks_in_outline.dart.weak.transformed.expect
index 56d2323..a688b79 100644
--- a/pkg/front_end/testcases/general/well_boundness_checks_in_outline.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/well_boundness_checks_in_outline.dart.weak.transformed.expect
@@ -61,7 +61,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<X extends core::int* = core::int*> extends core::Object {
+class A<X extends core::int*> extends core::Object {
   synthetic constructor •() → self::A<self::A::X*>*
     : super core::Object::•()
     ;
@@ -93,7 +93,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-extension E<X extends self::A<core::num*>* = self::A<core::num*>*> on self::A<core::int*>* {
+extension E<X extends self::A<core::num*>*> on self::A<core::int*>* {
   static field fieldOfE = self::E|fieldOfE;
   method fooOfE = self::E|fooOfE;
   tearoff fooOfE = self::E|get#fooOfE;
@@ -103,14 +103,14 @@
   tearoff bazOfE = self::E|get#bazOfE;
 }
 static field self::A<core::num*>* E|fieldOfE;
-static method E|fooOfE<X extends self::A<core::num*>* = self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → self::A<core::num*>*
+static method E|fooOfE<X extends self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → self::A<core::num*>*
   return null;
-static method E|get#fooOfE<X extends self::A<core::num*>* = self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → () →* self::A<core::num*>*
+static method E|get#fooOfE<X extends self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → () →* self::A<core::num*>*
   return () → self::A<core::num*>* => self::E|fooOfE<self::E|get#fooOfE::X*>(#this);
-static method E|barOfE<X extends self::A<core::num*>* = self::A<core::num*>*>(lowered final self::A<core::int*>* #this, self::A<core::num*>* a) → void {}
-static method E|get#barOfE<X extends self::A<core::num*>* = self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → (self::A<core::num*>*) →* void
+static method E|barOfE<X extends self::A<core::num*>*>(lowered final self::A<core::int*>* #this, self::A<core::num*>* a) → void {}
+static method E|get#barOfE<X extends self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → (self::A<core::num*>*) →* void
   return (self::A<core::num*>* a) → void => self::E|barOfE<self::E|get#barOfE::X*>(#this, a);
-static method E|bazOfE<X extends self::A<core::num*>* = self::A<core::num*>*, Y extends self::A<core::num*>* = self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → void {}
-static method E|get#bazOfE<X extends self::A<core::num*>* = self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → <Y extends self::A<core::num*>* = self::A<core::num*>*>() →* void
-  return <Y extends self::A<core::num*>* = self::A<core::num*>*>() → void => self::E|bazOfE<self::E|get#bazOfE::X*, Y*>(#this);
+static method E|bazOfE<X extends self::A<core::num*>*, Y extends self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → void {}
+static method E|get#bazOfE<X extends self::A<core::num*>*>(lowered final self::A<core::int*>* #this) → <Y extends self::A<core::num*>*>() →* void
+  return <Y extends self::A<core::num*>*>() → void => self::E|bazOfE<self::E|get#bazOfE::X*, Y*>(#this);
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/generic_metadata/erroneous_function_type_parameter.dart.strong.expect b/pkg/front_end/testcases/generic_metadata/erroneous_function_type_parameter.dart.strong.expect
index 6ab9190..5d340a4 100644
--- a/pkg/front_end/testcases/generic_metadata/erroneous_function_type_parameter.dart.strong.expect
+++ b/pkg/front_end/testcases/generic_metadata/erroneous_function_type_parameter.dart.strong.expect
@@ -56,7 +56,7 @@
     : super core::Object::•()
     ;
 }
-class Class<T extends <S extends core::Object? = dynamic>(S%) → void = <S extends core::Object? = dynamic>(S%) → void> extends core::Object {
+class Class<T extends <S extends core::Object? = dynamic>(S%) → void> extends core::Object {
   synthetic constructor •() → self::Class<self::Class::T>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/generic_metadata/erroneous_function_type_parameter.dart.strong.transformed.expect b/pkg/front_end/testcases/generic_metadata/erroneous_function_type_parameter.dart.strong.transformed.expect
index 6ab9190..5d340a4 100644
--- a/pkg/front_end/testcases/generic_metadata/erroneous_function_type_parameter.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/generic_metadata/erroneous_function_type_parameter.dart.strong.transformed.expect
@@ -56,7 +56,7 @@
     : super core::Object::•()
     ;
 }
-class Class<T extends <S extends core::Object? = dynamic>(S%) → void = <S extends core::Object? = dynamic>(S%) → void> extends core::Object {
+class Class<T extends <S extends core::Object? = dynamic>(S%) → void> extends core::Object {
   synthetic constructor •() → self::Class<self::Class::T>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/generic_metadata/erroneous_function_type_parameter.dart.weak.expect b/pkg/front_end/testcases/generic_metadata/erroneous_function_type_parameter.dart.weak.expect
index 6ab9190..5d340a4 100644
--- a/pkg/front_end/testcases/generic_metadata/erroneous_function_type_parameter.dart.weak.expect
+++ b/pkg/front_end/testcases/generic_metadata/erroneous_function_type_parameter.dart.weak.expect
@@ -56,7 +56,7 @@
     : super core::Object::•()
     ;
 }
-class Class<T extends <S extends core::Object? = dynamic>(S%) → void = <S extends core::Object? = dynamic>(S%) → void> extends core::Object {
+class Class<T extends <S extends core::Object? = dynamic>(S%) → void> extends core::Object {
   synthetic constructor •() → self::Class<self::Class::T>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/generic_metadata/erroneous_function_type_parameter.dart.weak.outline.expect b/pkg/front_end/testcases/generic_metadata/erroneous_function_type_parameter.dart.weak.outline.expect
index edc7f22..a2d0339 100644
--- a/pkg/front_end/testcases/generic_metadata/erroneous_function_type_parameter.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/generic_metadata/erroneous_function_type_parameter.dart.weak.outline.expect
@@ -28,7 +28,7 @@
     : super core::Object::•()
     ;
 }
-class Class<T extends <S extends core::Object? = dynamic>(S%) → void = <S extends core::Object? = dynamic>(S%) → void> extends core::Object {
+class Class<T extends <S extends core::Object? = dynamic>(S%) → void> extends core::Object {
   synthetic constructor •() → self::Class<self::Class::T>
     ;
 }
diff --git a/pkg/front_end/testcases/generic_metadata/erroneous_function_type_parameter.dart.weak.transformed.expect b/pkg/front_end/testcases/generic_metadata/erroneous_function_type_parameter.dart.weak.transformed.expect
index 6ab9190..5d340a4 100644
--- a/pkg/front_end/testcases/generic_metadata/erroneous_function_type_parameter.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/generic_metadata/erroneous_function_type_parameter.dart.weak.transformed.expect
@@ -56,7 +56,7 @@
     : super core::Object::•()
     ;
 }
-class Class<T extends <S extends core::Object? = dynamic>(S%) → void = <S extends core::Object? = dynamic>(S%) → void> extends core::Object {
+class Class<T extends <S extends core::Object? = dynamic>(S%) → void> extends core::Object {
   synthetic constructor •() → self::Class<self::Class::T>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/generic_metadata/from_dill/main.dart.strong.expect b/pkg/front_end/testcases/generic_metadata/from_dill/main.dart.strong.expect
index 92b41bb..189f2c4 100644
--- a/pkg/front_end/testcases/generic_metadata/from_dill/main.dart.strong.expect
+++ b/pkg/front_end/testcases/generic_metadata/from_dill/main.dart.strong.expect
@@ -15,9 +15,9 @@
   mai::C4<<T extends core::Object? = dynamic>(T%) → void> c7 = new mai::C4::•<<T extends core::Object? = dynamic>(T%) → void>();
   mai::C4<<T extends core::Object? = dynamic>(T%) → void> c8 = new mai::C4::•<<T extends core::Object? = dynamic>(T%) → void>();
   mai::C5<<T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T> c9 = new mai::C5::•<<T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T>();
-  mai::C5<<T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T> c10 = new mai::C5::•<<T extends <S extends core::Object? = dynamic>(S%) → S% = <S extends core::Object? = dynamic>(S%) → S%>(T) → T>();
+  mai::C5<<T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T> c10 = new mai::C5::•<<T extends <S extends core::Object? = dynamic>(S%) → S%>(T) → T>();
   mai::C6<<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%> c11 = new mai::C6::•<<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%>();
-  mai::C6<<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%> c12 = new mai::C6::•<<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = S%, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%>();
+  mai::C6<<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%> c12 = new mai::C6::•<<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S%, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%>();
 }
 
 library /*isNonNullableByDefault*/;
@@ -30,37 +30,37 @@
 typedef exp4 = <T extends core::Object? = dynamic>(T%) → void;
 typedef exp5 = <T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T;
 typedef exp6 = <T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%;
-class C1<X extends <T extends core::Object? = dynamic>(T%) → T% = <T extends core::Object? = dynamic>(T%) → T%> extends core::Object {
+class C1<X extends <T extends core::Object? = dynamic>(T%) → T%> extends core::Object {
   constructor •() → mai::C1<mai::C1::X>
     : super core::Object::•() {
     mai::expect(#C1, mai::C1::X);
   }
 }
-class C2<X extends <T extends core::Object? = dynamic>() → void = <T extends core::Object? = dynamic>() → void> extends core::Object {
+class C2<X extends <T extends core::Object? = dynamic>() → void> extends core::Object {
   constructor •() → mai::C2<mai::C2::X>
     : super core::Object::•() {
     mai::expect(#C2, mai::C2::X);
   }
 }
-class C3<X extends <T extends core::Object? = dynamic>() → T% = <T extends core::Object? = dynamic>() → T%> extends core::Object {
+class C3<X extends <T extends core::Object? = dynamic>() → T%> extends core::Object {
   constructor •() → mai::C3<mai::C3::X>
     : super core::Object::•() {
     mai::expect(#C3, mai::C3::X);
   }
 }
-class C4<X extends <T extends core::Object? = dynamic>(T%) → void = <T extends core::Object? = dynamic>(T%) → void> extends core::Object {
+class C4<X extends <T extends core::Object? = dynamic>(T%) → void> extends core::Object {
   constructor •() → mai::C4<mai::C4::X>
     : super core::Object::•() {
     mai::expect(#C4, mai::C4::X);
   }
 }
-class C5<X extends <T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T = <T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T> extends core::Object {
+class C5<X extends <T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T> extends core::Object {
   constructor •() → mai::C5<mai::C5::X>
     : super core::Object::•() {
     mai::expect(#C5, mai::C5::X);
   }
 }
-class C6<X extends <T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T% = <T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%> extends core::Object {
+class C6<X extends <T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%> extends core::Object {
   constructor •() → mai::C6<mai::C6::X>
     : super core::Object::•() {
     mai::expect(#C6, mai::C6::X);
diff --git a/pkg/front_end/testcases/generic_metadata/from_dill/main.dart.strong.transformed.expect b/pkg/front_end/testcases/generic_metadata/from_dill/main.dart.strong.transformed.expect
index 92b41bb..189f2c4 100644
--- a/pkg/front_end/testcases/generic_metadata/from_dill/main.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/generic_metadata/from_dill/main.dart.strong.transformed.expect
@@ -15,9 +15,9 @@
   mai::C4<<T extends core::Object? = dynamic>(T%) → void> c7 = new mai::C4::•<<T extends core::Object? = dynamic>(T%) → void>();
   mai::C4<<T extends core::Object? = dynamic>(T%) → void> c8 = new mai::C4::•<<T extends core::Object? = dynamic>(T%) → void>();
   mai::C5<<T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T> c9 = new mai::C5::•<<T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T>();
-  mai::C5<<T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T> c10 = new mai::C5::•<<T extends <S extends core::Object? = dynamic>(S%) → S% = <S extends core::Object? = dynamic>(S%) → S%>(T) → T>();
+  mai::C5<<T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T> c10 = new mai::C5::•<<T extends <S extends core::Object? = dynamic>(S%) → S%>(T) → T>();
   mai::C6<<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%> c11 = new mai::C6::•<<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%>();
-  mai::C6<<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%> c12 = new mai::C6::•<<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = S%, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%>();
+  mai::C6<<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%> c12 = new mai::C6::•<<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S%, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%>();
 }
 
 library /*isNonNullableByDefault*/;
@@ -30,37 +30,37 @@
 typedef exp4 = <T extends core::Object? = dynamic>(T%) → void;
 typedef exp5 = <T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T;
 typedef exp6 = <T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%;
-class C1<X extends <T extends core::Object? = dynamic>(T%) → T% = <T extends core::Object? = dynamic>(T%) → T%> extends core::Object {
+class C1<X extends <T extends core::Object? = dynamic>(T%) → T%> extends core::Object {
   constructor •() → mai::C1<mai::C1::X>
     : super core::Object::•() {
     mai::expect(#C1, mai::C1::X);
   }
 }
-class C2<X extends <T extends core::Object? = dynamic>() → void = <T extends core::Object? = dynamic>() → void> extends core::Object {
+class C2<X extends <T extends core::Object? = dynamic>() → void> extends core::Object {
   constructor •() → mai::C2<mai::C2::X>
     : super core::Object::•() {
     mai::expect(#C2, mai::C2::X);
   }
 }
-class C3<X extends <T extends core::Object? = dynamic>() → T% = <T extends core::Object? = dynamic>() → T%> extends core::Object {
+class C3<X extends <T extends core::Object? = dynamic>() → T%> extends core::Object {
   constructor •() → mai::C3<mai::C3::X>
     : super core::Object::•() {
     mai::expect(#C3, mai::C3::X);
   }
 }
-class C4<X extends <T extends core::Object? = dynamic>(T%) → void = <T extends core::Object? = dynamic>(T%) → void> extends core::Object {
+class C4<X extends <T extends core::Object? = dynamic>(T%) → void> extends core::Object {
   constructor •() → mai::C4<mai::C4::X>
     : super core::Object::•() {
     mai::expect(#C4, mai::C4::X);
   }
 }
-class C5<X extends <T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T = <T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T> extends core::Object {
+class C5<X extends <T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T> extends core::Object {
   constructor •() → mai::C5<mai::C5::X>
     : super core::Object::•() {
     mai::expect(#C5, mai::C5::X);
   }
 }
-class C6<X extends <T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T% = <T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%> extends core::Object {
+class C6<X extends <T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%> extends core::Object {
   constructor •() → mai::C6<mai::C6::X>
     : super core::Object::•() {
     mai::expect(#C6, mai::C6::X);
diff --git a/pkg/front_end/testcases/generic_metadata/from_dill/main.dart.weak.expect b/pkg/front_end/testcases/generic_metadata/from_dill/main.dart.weak.expect
index e1e7067..941af3f 100644
--- a/pkg/front_end/testcases/generic_metadata/from_dill/main.dart.weak.expect
+++ b/pkg/front_end/testcases/generic_metadata/from_dill/main.dart.weak.expect
@@ -15,9 +15,9 @@
   mai::C4<<T extends core::Object? = dynamic>(T%) → void> c7 = new mai::C4::•<<T extends core::Object? = dynamic>(T%) → void>();
   mai::C4<<T extends core::Object? = dynamic>(T%) → void> c8 = new mai::C4::•<<T extends core::Object? = dynamic>(T%) → void>();
   mai::C5<<T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T> c9 = new mai::C5::•<<T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T>();
-  mai::C5<<T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T> c10 = new mai::C5::•<<T extends <S extends core::Object? = dynamic>(S%) → S% = <S extends core::Object? = dynamic>(S%) → S%>(T) → T>();
+  mai::C5<<T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T> c10 = new mai::C5::•<<T extends <S extends core::Object? = dynamic>(S%) → S%>(T) → T>();
   mai::C6<<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%> c11 = new mai::C6::•<<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%>();
-  mai::C6<<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%> c12 = new mai::C6::•<<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = S%, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%>();
+  mai::C6<<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%> c12 = new mai::C6::•<<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S%, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%>();
 }
 
 library /*isNonNullableByDefault*/;
@@ -30,37 +30,37 @@
 typedef exp4 = <T extends core::Object? = dynamic>(T%) → void;
 typedef exp5 = <T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T;
 typedef exp6 = <T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%;
-class C1<X extends <T extends core::Object? = dynamic>(T%) → T% = <T extends core::Object? = dynamic>(T%) → T%> extends core::Object {
+class C1<X extends <T extends core::Object? = dynamic>(T%) → T%> extends core::Object {
   constructor •() → mai::C1<mai::C1::X>
     : super core::Object::•() {
     mai::expect(#C1, mai::C1::X);
   }
 }
-class C2<X extends <T extends core::Object? = dynamic>() → void = <T extends core::Object? = dynamic>() → void> extends core::Object {
+class C2<X extends <T extends core::Object? = dynamic>() → void> extends core::Object {
   constructor •() → mai::C2<mai::C2::X>
     : super core::Object::•() {
     mai::expect(#C2, mai::C2::X);
   }
 }
-class C3<X extends <T extends core::Object? = dynamic>() → T% = <T extends core::Object? = dynamic>() → T%> extends core::Object {
+class C3<X extends <T extends core::Object? = dynamic>() → T%> extends core::Object {
   constructor •() → mai::C3<mai::C3::X>
     : super core::Object::•() {
     mai::expect(#C3, mai::C3::X);
   }
 }
-class C4<X extends <T extends core::Object? = dynamic>(T%) → void = <T extends core::Object? = dynamic>(T%) → void> extends core::Object {
+class C4<X extends <T extends core::Object? = dynamic>(T%) → void> extends core::Object {
   constructor •() → mai::C4<mai::C4::X>
     : super core::Object::•() {
     mai::expect(#C4, mai::C4::X);
   }
 }
-class C5<X extends <T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T = <T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T> extends core::Object {
+class C5<X extends <T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T> extends core::Object {
   constructor •() → mai::C5<mai::C5::X>
     : super core::Object::•() {
     mai::expect(#C5, mai::C5::X);
   }
 }
-class C6<X extends <T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T% = <T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%> extends core::Object {
+class C6<X extends <T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%> extends core::Object {
   constructor •() → mai::C6<mai::C6::X>
     : super core::Object::•() {
     mai::expect(#C6, mai::C6::X);
@@ -76,6 +76,6 @@
   #C2 = TypeLiteralConstant(<T extends core::Object? = dynamic>() →* void)
   #C3 = TypeLiteralConstant(<T extends core::Object? = dynamic>() →* T*)
   #C4 = TypeLiteralConstant(<T extends core::Object? = dynamic>(T*) →* void)
-  #C5 = TypeLiteralConstant(<T extends <S extends core::Object? = dynamic>(S*) →* S* = <S extends core::Object? = dynamic>(S*) →* S*>(T*) →* T*)
-  #C6 = TypeLiteralConstant(<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T*, S*, <V extends S* = S*, U extends core::Object? = dynamic>(T*, U*, V*, core::Map<S*, U*>*) →* V*) →* T*)
+  #C5 = TypeLiteralConstant(<T extends <S extends core::Object? = dynamic>(S*) →* S*>(T*) →* T*)
+  #C6 = TypeLiteralConstant(<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T*, S*, <V extends S*, U extends core::Object? = dynamic>(T*, U*, V*, core::Map<S*, U*>*) →* V*) →* T*)
 }
diff --git a/pkg/front_end/testcases/generic_metadata/from_dill/main.dart.weak.outline.expect b/pkg/front_end/testcases/generic_metadata/from_dill/main.dart.weak.outline.expect
index b9ccc27..ba9fc54 100644
--- a/pkg/front_end/testcases/generic_metadata/from_dill/main.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/generic_metadata/from_dill/main.dart.weak.outline.expect
@@ -16,27 +16,27 @@
 typedef exp4 = <T extends core::Object? = dynamic>(T%) → void;
 typedef exp5 = <T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T;
 typedef exp6 = <T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%;
-class C1<X extends <T extends core::Object? = dynamic>(T%) → T% = <T extends core::Object? = dynamic>(T%) → T%> extends core::Object {
+class C1<X extends <T extends core::Object? = dynamic>(T%) → T%> extends core::Object {
   constructor •() → self2::C1<self2::C1::X>
     ;
 }
-class C2<X extends <T extends core::Object? = dynamic>() → void = <T extends core::Object? = dynamic>() → void> extends core::Object {
+class C2<X extends <T extends core::Object? = dynamic>() → void> extends core::Object {
   constructor •() → self2::C2<self2::C2::X>
     ;
 }
-class C3<X extends <T extends core::Object? = dynamic>() → T% = <T extends core::Object? = dynamic>() → T%> extends core::Object {
+class C3<X extends <T extends core::Object? = dynamic>() → T%> extends core::Object {
   constructor •() → self2::C3<self2::C3::X>
     ;
 }
-class C4<X extends <T extends core::Object? = dynamic>(T%) → void = <T extends core::Object? = dynamic>(T%) → void> extends core::Object {
+class C4<X extends <T extends core::Object? = dynamic>(T%) → void> extends core::Object {
   constructor •() → self2::C4<self2::C4::X>
     ;
 }
-class C5<X extends <T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T = <T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T> extends core::Object {
+class C5<X extends <T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T> extends core::Object {
   constructor •() → self2::C5<self2::C5::X>
     ;
 }
-class C6<X extends <T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T% = <T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%> extends core::Object {
+class C6<X extends <T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%> extends core::Object {
   constructor •() → self2::C6<self2::C6::X>
     ;
 }
diff --git a/pkg/front_end/testcases/generic_metadata/from_dill/main.dart.weak.transformed.expect b/pkg/front_end/testcases/generic_metadata/from_dill/main.dart.weak.transformed.expect
index e1e7067..941af3f 100644
--- a/pkg/front_end/testcases/generic_metadata/from_dill/main.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/generic_metadata/from_dill/main.dart.weak.transformed.expect
@@ -15,9 +15,9 @@
   mai::C4<<T extends core::Object? = dynamic>(T%) → void> c7 = new mai::C4::•<<T extends core::Object? = dynamic>(T%) → void>();
   mai::C4<<T extends core::Object? = dynamic>(T%) → void> c8 = new mai::C4::•<<T extends core::Object? = dynamic>(T%) → void>();
   mai::C5<<T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T> c9 = new mai::C5::•<<T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T>();
-  mai::C5<<T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T> c10 = new mai::C5::•<<T extends <S extends core::Object? = dynamic>(S%) → S% = <S extends core::Object? = dynamic>(S%) → S%>(T) → T>();
+  mai::C5<<T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T> c10 = new mai::C5::•<<T extends <S extends core::Object? = dynamic>(S%) → S%>(T) → T>();
   mai::C6<<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%> c11 = new mai::C6::•<<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%>();
-  mai::C6<<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%> c12 = new mai::C6::•<<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = S%, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%>();
+  mai::C6<<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%> c12 = new mai::C6::•<<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S%, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%>();
 }
 
 library /*isNonNullableByDefault*/;
@@ -30,37 +30,37 @@
 typedef exp4 = <T extends core::Object? = dynamic>(T%) → void;
 typedef exp5 = <T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T;
 typedef exp6 = <T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%;
-class C1<X extends <T extends core::Object? = dynamic>(T%) → T% = <T extends core::Object? = dynamic>(T%) → T%> extends core::Object {
+class C1<X extends <T extends core::Object? = dynamic>(T%) → T%> extends core::Object {
   constructor •() → mai::C1<mai::C1::X>
     : super core::Object::•() {
     mai::expect(#C1, mai::C1::X);
   }
 }
-class C2<X extends <T extends core::Object? = dynamic>() → void = <T extends core::Object? = dynamic>() → void> extends core::Object {
+class C2<X extends <T extends core::Object? = dynamic>() → void> extends core::Object {
   constructor •() → mai::C2<mai::C2::X>
     : super core::Object::•() {
     mai::expect(#C2, mai::C2::X);
   }
 }
-class C3<X extends <T extends core::Object? = dynamic>() → T% = <T extends core::Object? = dynamic>() → T%> extends core::Object {
+class C3<X extends <T extends core::Object? = dynamic>() → T%> extends core::Object {
   constructor •() → mai::C3<mai::C3::X>
     : super core::Object::•() {
     mai::expect(#C3, mai::C3::X);
   }
 }
-class C4<X extends <T extends core::Object? = dynamic>(T%) → void = <T extends core::Object? = dynamic>(T%) → void> extends core::Object {
+class C4<X extends <T extends core::Object? = dynamic>(T%) → void> extends core::Object {
   constructor •() → mai::C4<mai::C4::X>
     : super core::Object::•() {
     mai::expect(#C4, mai::C4::X);
   }
 }
-class C5<X extends <T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T = <T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T> extends core::Object {
+class C5<X extends <T extends <S extends core::Object? = dynamic>(S%) → S% = dynamic>(T) → T> extends core::Object {
   constructor •() → mai::C5<mai::C5::X>
     : super core::Object::•() {
     mai::expect(#C5, mai::C5::X);
   }
 }
-class C6<X extends <T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T% = <T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%> extends core::Object {
+class C6<X extends <T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T%, S%, <V extends S% = dynamic, U extends core::Object? = dynamic>(T%, U%, V%, core::Map<S%, U%>) → V%) → T%> extends core::Object {
   constructor •() → mai::C6<mai::C6::X>
     : super core::Object::•() {
     mai::expect(#C6, mai::C6::X);
@@ -76,6 +76,6 @@
   #C2 = TypeLiteralConstant(<T extends core::Object? = dynamic>() →* void)
   #C3 = TypeLiteralConstant(<T extends core::Object? = dynamic>() →* T*)
   #C4 = TypeLiteralConstant(<T extends core::Object? = dynamic>(T*) →* void)
-  #C5 = TypeLiteralConstant(<T extends <S extends core::Object? = dynamic>(S*) →* S* = <S extends core::Object? = dynamic>(S*) →* S*>(T*) →* T*)
-  #C6 = TypeLiteralConstant(<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T*, S*, <V extends S* = S*, U extends core::Object? = dynamic>(T*, U*, V*, core::Map<S*, U*>*) →* V*) →* T*)
+  #C5 = TypeLiteralConstant(<T extends <S extends core::Object? = dynamic>(S*) →* S*>(T*) →* T*)
+  #C6 = TypeLiteralConstant(<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(T*, S*, <V extends S*, U extends core::Object? = dynamic>(T*, U*, V*, core::Map<S*, U*>*) →* V*) →* T*)
 }
diff --git a/pkg/front_end/testcases/generic_metadata/function_type_parameter.dart.strong.expect b/pkg/front_end/testcases/generic_metadata/function_type_parameter.dart.strong.expect
index 493cc77..17eab83 100644
--- a/pkg/front_end/testcases/generic_metadata/function_type_parameter.dart.strong.expect
+++ b/pkg/front_end/testcases/generic_metadata/function_type_parameter.dart.strong.expect
@@ -9,7 +9,7 @@
     : super core::Object::•()
     ;
 }
-class Class<T extends <S extends core::Object? = dynamic>(S%) → void = <S extends core::Object? = dynamic>(S%) → void> extends core::Object {
+class Class<T extends <S extends core::Object? = dynamic>(S%) → void> extends core::Object {
   synthetic constructor •() → self::Class<self::Class::T>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/generic_metadata/function_type_parameter.dart.strong.transformed.expect b/pkg/front_end/testcases/generic_metadata/function_type_parameter.dart.strong.transformed.expect
index 493cc77..17eab83 100644
--- a/pkg/front_end/testcases/generic_metadata/function_type_parameter.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/generic_metadata/function_type_parameter.dart.strong.transformed.expect
@@ -9,7 +9,7 @@
     : super core::Object::•()
     ;
 }
-class Class<T extends <S extends core::Object? = dynamic>(S%) → void = <S extends core::Object? = dynamic>(S%) → void> extends core::Object {
+class Class<T extends <S extends core::Object? = dynamic>(S%) → void> extends core::Object {
   synthetic constructor •() → self::Class<self::Class::T>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/generic_metadata/function_type_parameter.dart.weak.expect b/pkg/front_end/testcases/generic_metadata/function_type_parameter.dart.weak.expect
index c1ead73..d081a19 100644
--- a/pkg/front_end/testcases/generic_metadata/function_type_parameter.dart.weak.expect
+++ b/pkg/front_end/testcases/generic_metadata/function_type_parameter.dart.weak.expect
@@ -9,7 +9,7 @@
     : super core::Object::•()
     ;
 }
-class Class<T extends <S extends core::Object? = dynamic>(S%) → void = <S extends core::Object? = dynamic>(S%) → void> extends core::Object {
+class Class<T extends <S extends core::Object? = dynamic>(S%) → void> extends core::Object {
   synthetic constructor •() → self::Class<self::Class::T>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/generic_metadata/function_type_parameter.dart.weak.outline.expect b/pkg/front_end/testcases/generic_metadata/function_type_parameter.dart.weak.outline.expect
index 778e91b..7735bd6 100644
--- a/pkg/front_end/testcases/generic_metadata/function_type_parameter.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/generic_metadata/function_type_parameter.dart.weak.outline.expect
@@ -9,7 +9,7 @@
     : super core::Object::•()
     ;
 }
-class Class<T extends <S extends core::Object? = dynamic>(S%) → void = <S extends core::Object? = dynamic>(S%) → void> extends core::Object {
+class Class<T extends <S extends core::Object? = dynamic>(S%) → void> extends core::Object {
   synthetic constructor •() → self::Class<self::Class::T>
     ;
 }
diff --git a/pkg/front_end/testcases/generic_metadata/function_type_parameter.dart.weak.transformed.expect b/pkg/front_end/testcases/generic_metadata/function_type_parameter.dart.weak.transformed.expect
index c1ead73..d081a19 100644
--- a/pkg/front_end/testcases/generic_metadata/function_type_parameter.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/generic_metadata/function_type_parameter.dart.weak.transformed.expect
@@ -9,7 +9,7 @@
     : super core::Object::•()
     ;
 }
-class Class<T extends <S extends core::Object? = dynamic>(S%) → void = <S extends core::Object? = dynamic>(S%) → void> extends core::Object {
+class Class<T extends <S extends core::Object? = dynamic>(S%) → void> extends core::Object {
   synthetic constructor •() → self::Class<self::Class::T>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/generic_metadata/generic_metadata.dart.strong.expect b/pkg/front_end/testcases/generic_metadata/generic_metadata.dart.strong.expect
index d7ddced..0054d6c 100644
--- a/pkg/front_end/testcases/generic_metadata/generic_metadata.dart.strong.expect
+++ b/pkg/front_end/testcases/generic_metadata/generic_metadata.dart.strong.expect
@@ -45,12 +45,12 @@
     : super core::Object::•()
     ;
 }
-class C<T extends core::num = core::num> extends core::Object /*hasConstConstructor*/  {
+class C<T extends core::num> extends core::Object /*hasConstConstructor*/  {
   const constructor •() → self::C<self::C::T>
     : super core::Object::•()
     ;
 }
-class D<S extends core::num = core::num, T extends self::D::S = core::num> extends core::Object /*hasConstConstructor*/  {
+class D<S extends core::num, T extends self::D::S = core::num> extends core::Object /*hasConstConstructor*/  {
   const constructor •() → self::D<self::D::S, self::D::T>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/generic_metadata/generic_metadata.dart.strong.transformed.expect b/pkg/front_end/testcases/generic_metadata/generic_metadata.dart.strong.transformed.expect
index d7ddced..0054d6c 100644
--- a/pkg/front_end/testcases/generic_metadata/generic_metadata.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/generic_metadata/generic_metadata.dart.strong.transformed.expect
@@ -45,12 +45,12 @@
     : super core::Object::•()
     ;
 }
-class C<T extends core::num = core::num> extends core::Object /*hasConstConstructor*/  {
+class C<T extends core::num> extends core::Object /*hasConstConstructor*/  {
   const constructor •() → self::C<self::C::T>
     : super core::Object::•()
     ;
 }
-class D<S extends core::num = core::num, T extends self::D::S = core::num> extends core::Object /*hasConstConstructor*/  {
+class D<S extends core::num, T extends self::D::S = core::num> extends core::Object /*hasConstConstructor*/  {
   const constructor •() → self::D<self::D::S, self::D::T>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/generic_metadata/generic_metadata.dart.weak.expect b/pkg/front_end/testcases/generic_metadata/generic_metadata.dart.weak.expect
index 338bb8d..b60d2ce 100644
--- a/pkg/front_end/testcases/generic_metadata/generic_metadata.dart.weak.expect
+++ b/pkg/front_end/testcases/generic_metadata/generic_metadata.dart.weak.expect
@@ -45,12 +45,12 @@
     : super core::Object::•()
     ;
 }
-class C<T extends core::num = core::num> extends core::Object /*hasConstConstructor*/  {
+class C<T extends core::num> extends core::Object /*hasConstConstructor*/  {
   const constructor •() → self::C<self::C::T>
     : super core::Object::•()
     ;
 }
-class D<S extends core::num = core::num, T extends self::D::S = core::num> extends core::Object /*hasConstConstructor*/  {
+class D<S extends core::num, T extends self::D::S = core::num> extends core::Object /*hasConstConstructor*/  {
   const constructor •() → self::D<self::D::S, self::D::T>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/generic_metadata/generic_metadata.dart.weak.outline.expect b/pkg/front_end/testcases/generic_metadata/generic_metadata.dart.weak.outline.expect
index 229b1bb..71f6cda 100644
--- a/pkg/front_end/testcases/generic_metadata/generic_metadata.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/generic_metadata/generic_metadata.dart.weak.outline.expect
@@ -45,12 +45,12 @@
     : super core::Object::•()
     ;
 }
-class C<T extends core::num = core::num> extends core::Object /*hasConstConstructor*/  {
+class C<T extends core::num> extends core::Object /*hasConstConstructor*/  {
   const constructor •() → self::C<self::C::T>
     : super core::Object::•()
     ;
 }
-class D<S extends core::num = core::num, T extends self::D::S = core::num> extends core::Object /*hasConstConstructor*/  {
+class D<S extends core::num, T extends self::D::S = core::num> extends core::Object /*hasConstConstructor*/  {
   const constructor •() → self::D<self::D::S, self::D::T>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/generic_metadata/generic_metadata.dart.weak.transformed.expect b/pkg/front_end/testcases/generic_metadata/generic_metadata.dart.weak.transformed.expect
index 338bb8d..b60d2ce 100644
--- a/pkg/front_end/testcases/generic_metadata/generic_metadata.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/generic_metadata/generic_metadata.dart.weak.transformed.expect
@@ -45,12 +45,12 @@
     : super core::Object::•()
     ;
 }
-class C<T extends core::num = core::num> extends core::Object /*hasConstConstructor*/  {
+class C<T extends core::num> extends core::Object /*hasConstConstructor*/  {
   const constructor •() → self::C<self::C::T>
     : super core::Object::•()
     ;
 }
-class D<S extends core::num = core::num, T extends self::D::S = core::num> extends core::Object /*hasConstConstructor*/  {
+class D<S extends core::num, T extends self::D::S = core::num> extends core::Object /*hasConstConstructor*/  {
   const constructor •() → self::D<self::D::S, self::D::T>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/generic_metadata/issue45330.dart.strong.expect b/pkg/front_end/testcases/generic_metadata/issue45330.dart.strong.expect
index bf8ebf6..156f3fb 100644
--- a/pkg/front_end/testcases/generic_metadata/issue45330.dart.strong.expect
+++ b/pkg/front_end/testcases/generic_metadata/issue45330.dart.strong.expect
@@ -18,9 +18,9 @@
 part issue45330_lib.dart;
 static method genericMethod<T extends core::Object? = dynamic>() → void {}
 static method testInMain() → dynamic {
-  self::genericMethod<<T extends invalid-type = invalid-type>() → void>();
+  self::genericMethod<<T extends invalid-type>() → void>();
 }
 static method main() → dynamic {}
 static method /* from org-dartlang-testcase:///issue45330_lib.dart */ testInPart() → dynamic {
-  self::genericMethod<<T extends invalid-type = invalid-type>() → void>();
+  self::genericMethod<<T extends invalid-type>() → void>();
 }
diff --git a/pkg/front_end/testcases/generic_metadata/issue45330.dart.strong.transformed.expect b/pkg/front_end/testcases/generic_metadata/issue45330.dart.strong.transformed.expect
index bf8ebf6..156f3fb 100644
--- a/pkg/front_end/testcases/generic_metadata/issue45330.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/generic_metadata/issue45330.dart.strong.transformed.expect
@@ -18,9 +18,9 @@
 part issue45330_lib.dart;
 static method genericMethod<T extends core::Object? = dynamic>() → void {}
 static method testInMain() → dynamic {
-  self::genericMethod<<T extends invalid-type = invalid-type>() → void>();
+  self::genericMethod<<T extends invalid-type>() → void>();
 }
 static method main() → dynamic {}
 static method /* from org-dartlang-testcase:///issue45330_lib.dart */ testInPart() → dynamic {
-  self::genericMethod<<T extends invalid-type = invalid-type>() → void>();
+  self::genericMethod<<T extends invalid-type>() → void>();
 }
diff --git a/pkg/front_end/testcases/generic_metadata/issue45330.dart.weak.expect b/pkg/front_end/testcases/generic_metadata/issue45330.dart.weak.expect
index bf8ebf6..156f3fb 100644
--- a/pkg/front_end/testcases/generic_metadata/issue45330.dart.weak.expect
+++ b/pkg/front_end/testcases/generic_metadata/issue45330.dart.weak.expect
@@ -18,9 +18,9 @@
 part issue45330_lib.dart;
 static method genericMethod<T extends core::Object? = dynamic>() → void {}
 static method testInMain() → dynamic {
-  self::genericMethod<<T extends invalid-type = invalid-type>() → void>();
+  self::genericMethod<<T extends invalid-type>() → void>();
 }
 static method main() → dynamic {}
 static method /* from org-dartlang-testcase:///issue45330_lib.dart */ testInPart() → dynamic {
-  self::genericMethod<<T extends invalid-type = invalid-type>() → void>();
+  self::genericMethod<<T extends invalid-type>() → void>();
 }
diff --git a/pkg/front_end/testcases/generic_metadata/issue45330.dart.weak.transformed.expect b/pkg/front_end/testcases/generic_metadata/issue45330.dart.weak.transformed.expect
index bf8ebf6..156f3fb 100644
--- a/pkg/front_end/testcases/generic_metadata/issue45330.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/generic_metadata/issue45330.dart.weak.transformed.expect
@@ -18,9 +18,9 @@
 part issue45330_lib.dart;
 static method genericMethod<T extends core::Object? = dynamic>() → void {}
 static method testInMain() → dynamic {
-  self::genericMethod<<T extends invalid-type = invalid-type>() → void>();
+  self::genericMethod<<T extends invalid-type>() → void>();
 }
 static method main() → dynamic {}
 static method /* from org-dartlang-testcase:///issue45330_lib.dart */ testInPart() → dynamic {
-  self::genericMethod<<T extends invalid-type = invalid-type>() → void>();
+  self::genericMethod<<T extends invalid-type>() → void>();
 }
diff --git a/pkg/front_end/testcases/generic_metadata/simple_generic_types_in_arguments_and_bounds.dart.strong.expect b/pkg/front_end/testcases/generic_metadata/simple_generic_types_in_arguments_and_bounds.dart.strong.expect
index 0777872..3c45ce6 100644
--- a/pkg/front_end/testcases/generic_metadata/simple_generic_types_in_arguments_and_bounds.dart.strong.expect
+++ b/pkg/front_end/testcases/generic_metadata/simple_generic_types_in_arguments_and_bounds.dart.strong.expect
@@ -12,13 +12,13 @@
     : super self::A::•()
     ;
 }
-class C<Z extends <Y extends core::Object? = dynamic>(Y%) → dynamic = <Y extends core::Object? = dynamic>(Y%) → dynamic> extends core::Object {
+class C<Z extends <Y extends core::Object? = dynamic>(Y%) → dynamic> extends core::Object {
   synthetic constructor •() → self::C<self::C::Z>
     : super core::Object::•()
     ;
 }
 static method foo(self::A<<Y extends core::Object? = dynamic>(Y%) → dynamic> x) → self::A<<Y extends core::Object? = dynamic>(Y%) → dynamic>
   return throw 42;
-static method bar<V extends <Y extends core::Object? = dynamic>(Y%) → dynamic = <Y extends core::Object? = dynamic>(Y%) → dynamic>() → dynamic
+static method bar<V extends <Y extends core::Object? = dynamic>(Y%) → dynamic>() → dynamic
   return throw 42;
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/generic_metadata/simple_generic_types_in_arguments_and_bounds.dart.strong.transformed.expect b/pkg/front_end/testcases/generic_metadata/simple_generic_types_in_arguments_and_bounds.dart.strong.transformed.expect
index 0777872..3c45ce6 100644
--- a/pkg/front_end/testcases/generic_metadata/simple_generic_types_in_arguments_and_bounds.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/generic_metadata/simple_generic_types_in_arguments_and_bounds.dart.strong.transformed.expect
@@ -12,13 +12,13 @@
     : super self::A::•()
     ;
 }
-class C<Z extends <Y extends core::Object? = dynamic>(Y%) → dynamic = <Y extends core::Object? = dynamic>(Y%) → dynamic> extends core::Object {
+class C<Z extends <Y extends core::Object? = dynamic>(Y%) → dynamic> extends core::Object {
   synthetic constructor •() → self::C<self::C::Z>
     : super core::Object::•()
     ;
 }
 static method foo(self::A<<Y extends core::Object? = dynamic>(Y%) → dynamic> x) → self::A<<Y extends core::Object? = dynamic>(Y%) → dynamic>
   return throw 42;
-static method bar<V extends <Y extends core::Object? = dynamic>(Y%) → dynamic = <Y extends core::Object? = dynamic>(Y%) → dynamic>() → dynamic
+static method bar<V extends <Y extends core::Object? = dynamic>(Y%) → dynamic>() → dynamic
   return throw 42;
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/generic_metadata/simple_generic_types_in_arguments_and_bounds.dart.weak.expect b/pkg/front_end/testcases/generic_metadata/simple_generic_types_in_arguments_and_bounds.dart.weak.expect
index 0777872..3c45ce6 100644
--- a/pkg/front_end/testcases/generic_metadata/simple_generic_types_in_arguments_and_bounds.dart.weak.expect
+++ b/pkg/front_end/testcases/generic_metadata/simple_generic_types_in_arguments_and_bounds.dart.weak.expect
@@ -12,13 +12,13 @@
     : super self::A::•()
     ;
 }
-class C<Z extends <Y extends core::Object? = dynamic>(Y%) → dynamic = <Y extends core::Object? = dynamic>(Y%) → dynamic> extends core::Object {
+class C<Z extends <Y extends core::Object? = dynamic>(Y%) → dynamic> extends core::Object {
   synthetic constructor •() → self::C<self::C::Z>
     : super core::Object::•()
     ;
 }
 static method foo(self::A<<Y extends core::Object? = dynamic>(Y%) → dynamic> x) → self::A<<Y extends core::Object? = dynamic>(Y%) → dynamic>
   return throw 42;
-static method bar<V extends <Y extends core::Object? = dynamic>(Y%) → dynamic = <Y extends core::Object? = dynamic>(Y%) → dynamic>() → dynamic
+static method bar<V extends <Y extends core::Object? = dynamic>(Y%) → dynamic>() → dynamic
   return throw 42;
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/generic_metadata/simple_generic_types_in_arguments_and_bounds.dart.weak.outline.expect b/pkg/front_end/testcases/generic_metadata/simple_generic_types_in_arguments_and_bounds.dart.weak.outline.expect
index 13fcc95..98c0d38 100644
--- a/pkg/front_end/testcases/generic_metadata/simple_generic_types_in_arguments_and_bounds.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/generic_metadata/simple_generic_types_in_arguments_and_bounds.dart.weak.outline.expect
@@ -10,13 +10,13 @@
   synthetic constructor •() → self::B
     ;
 }
-class C<Z extends <Y extends core::Object? = dynamic>(Y%) → dynamic = <Y extends core::Object? = dynamic>(Y%) → dynamic> extends core::Object {
+class C<Z extends <Y extends core::Object? = dynamic>(Y%) → dynamic> extends core::Object {
   synthetic constructor •() → self::C<self::C::Z>
     ;
 }
 static method foo(self::A<<Y extends core::Object? = dynamic>(Y%) → dynamic> x) → self::A<<Y extends core::Object? = dynamic>(Y%) → dynamic>
   ;
-static method bar<V extends <Y extends core::Object? = dynamic>(Y%) → dynamic = <Y extends core::Object? = dynamic>(Y%) → dynamic>() → dynamic
+static method bar<V extends <Y extends core::Object? = dynamic>(Y%) → dynamic>() → dynamic
   ;
 static method main() → dynamic
   ;
diff --git a/pkg/front_end/testcases/generic_metadata/simple_generic_types_in_arguments_and_bounds.dart.weak.transformed.expect b/pkg/front_end/testcases/generic_metadata/simple_generic_types_in_arguments_and_bounds.dart.weak.transformed.expect
index 0777872..3c45ce6 100644
--- a/pkg/front_end/testcases/generic_metadata/simple_generic_types_in_arguments_and_bounds.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/generic_metadata/simple_generic_types_in_arguments_and_bounds.dart.weak.transformed.expect
@@ -12,13 +12,13 @@
     : super self::A::•()
     ;
 }
-class C<Z extends <Y extends core::Object? = dynamic>(Y%) → dynamic = <Y extends core::Object? = dynamic>(Y%) → dynamic> extends core::Object {
+class C<Z extends <Y extends core::Object? = dynamic>(Y%) → dynamic> extends core::Object {
   synthetic constructor •() → self::C<self::C::Z>
     : super core::Object::•()
     ;
 }
 static method foo(self::A<<Y extends core::Object? = dynamic>(Y%) → dynamic> x) → self::A<<Y extends core::Object? = dynamic>(Y%) → dynamic>
   return throw 42;
-static method bar<V extends <Y extends core::Object? = dynamic>(Y%) → dynamic = <Y extends core::Object? = dynamic>(Y%) → dynamic>() → dynamic
+static method bar<V extends <Y extends core::Object? = dynamic>(Y%) → dynamic>() → dynamic
   return throw 42;
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/generic_metadata/type_parameters_in_default_types.dart.strong.expect b/pkg/front_end/testcases/generic_metadata/type_parameters_in_default_types.dart.strong.expect
index 52d8793..f970a2a 100644
--- a/pkg/front_end/testcases/generic_metadata/type_parameters_in_default_types.dart.strong.expect
+++ b/pkg/front_end/testcases/generic_metadata/type_parameters_in_default_types.dart.strong.expect
@@ -1,5 +1,5 @@
 library /*isNonNullableByDefault*/;
 import self as self;
 
-static method foo<X extends <Y extends self::foo::X = dynamic>() → dynamic = <Y extends dynamic = dynamic>() → dynamic>() → dynamic {}
+static method foo<X extends <Y extends self::foo::X = dynamic>() → dynamic = <Y extends dynamic>() → dynamic>() → dynamic {}
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/generic_metadata/type_parameters_in_default_types.dart.strong.transformed.expect b/pkg/front_end/testcases/generic_metadata/type_parameters_in_default_types.dart.strong.transformed.expect
index 52d8793..f970a2a 100644
--- a/pkg/front_end/testcases/generic_metadata/type_parameters_in_default_types.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/generic_metadata/type_parameters_in_default_types.dart.strong.transformed.expect
@@ -1,5 +1,5 @@
 library /*isNonNullableByDefault*/;
 import self as self;
 
-static method foo<X extends <Y extends self::foo::X = dynamic>() → dynamic = <Y extends dynamic = dynamic>() → dynamic>() → dynamic {}
+static method foo<X extends <Y extends self::foo::X = dynamic>() → dynamic = <Y extends dynamic>() → dynamic>() → dynamic {}
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/generic_metadata/type_parameters_in_default_types.dart.weak.expect b/pkg/front_end/testcases/generic_metadata/type_parameters_in_default_types.dart.weak.expect
index 52d8793..f970a2a 100644
--- a/pkg/front_end/testcases/generic_metadata/type_parameters_in_default_types.dart.weak.expect
+++ b/pkg/front_end/testcases/generic_metadata/type_parameters_in_default_types.dart.weak.expect
@@ -1,5 +1,5 @@
 library /*isNonNullableByDefault*/;
 import self as self;
 
-static method foo<X extends <Y extends self::foo::X = dynamic>() → dynamic = <Y extends dynamic = dynamic>() → dynamic>() → dynamic {}
+static method foo<X extends <Y extends self::foo::X = dynamic>() → dynamic = <Y extends dynamic>() → dynamic>() → dynamic {}
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/generic_metadata/type_parameters_in_default_types.dart.weak.outline.expect b/pkg/front_end/testcases/generic_metadata/type_parameters_in_default_types.dart.weak.outline.expect
index 3b0732a..e413c7d 100644
--- a/pkg/front_end/testcases/generic_metadata/type_parameters_in_default_types.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/generic_metadata/type_parameters_in_default_types.dart.weak.outline.expect
@@ -1,7 +1,7 @@
 library /*isNonNullableByDefault*/;
 import self as self;
 
-static method foo<X extends <Y extends self::foo::X = dynamic>() → dynamic = <Y extends dynamic = dynamic>() → dynamic>() → dynamic
+static method foo<X extends <Y extends self::foo::X = dynamic>() → dynamic = <Y extends dynamic>() → dynamic>() → dynamic
   ;
 static method main() → dynamic
   ;
diff --git a/pkg/front_end/testcases/generic_metadata/type_parameters_in_default_types.dart.weak.transformed.expect b/pkg/front_end/testcases/generic_metadata/type_parameters_in_default_types.dart.weak.transformed.expect
index 52d8793..f970a2a 100644
--- a/pkg/front_end/testcases/generic_metadata/type_parameters_in_default_types.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/generic_metadata/type_parameters_in_default_types.dart.weak.transformed.expect
@@ -1,5 +1,5 @@
 library /*isNonNullableByDefault*/;
 import self as self;
 
-static method foo<X extends <Y extends self::foo::X = dynamic>() → dynamic = <Y extends dynamic = dynamic>() → dynamic>() → dynamic {}
+static method foo<X extends <Y extends self::foo::X = dynamic>() → dynamic = <Y extends dynamic>() → dynamic>() → dynamic {}
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/generic_metadata/typedef_generic_types_in_arguments_and_bounds.dart.strong.expect b/pkg/front_end/testcases/generic_metadata/typedef_generic_types_in_arguments_and_bounds.dart.strong.expect
index dd20ce4..e853954 100644
--- a/pkg/front_end/testcases/generic_metadata/typedef_generic_types_in_arguments_and_bounds.dart.strong.expect
+++ b/pkg/front_end/testcases/generic_metadata/typedef_generic_types_in_arguments_and_bounds.dart.strong.expect
@@ -13,13 +13,13 @@
     : super self::A::•()
     ;
 }
-class C<Z extends <Y extends core::Object? = dynamic>(Y%) → dynamic = <Y extends core::Object? = dynamic>(Y%) → dynamic> extends core::Object {
+class C<Z extends <Y extends core::Object? = dynamic>(Y%) → dynamic> extends core::Object {
   synthetic constructor •() → self::C<self::C::Z>
     : super core::Object::•()
     ;
 }
 static method foo(self::A<<Y extends core::Object? = dynamic>(Y%) → dynamic> x) → self::A<<Y extends core::Object? = dynamic>(Y%) → dynamic>
   return throw 42;
-static method bar<V extends <Y extends core::Object? = dynamic>(Y%) → dynamic = <Y extends core::Object? = dynamic>(Y%) → dynamic>() → dynamic
+static method bar<V extends <Y extends core::Object? = dynamic>(Y%) → dynamic>() → dynamic
   return throw 42;
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/generic_metadata/typedef_generic_types_in_arguments_and_bounds.dart.strong.transformed.expect b/pkg/front_end/testcases/generic_metadata/typedef_generic_types_in_arguments_and_bounds.dart.strong.transformed.expect
index dd20ce4..e853954 100644
--- a/pkg/front_end/testcases/generic_metadata/typedef_generic_types_in_arguments_and_bounds.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/generic_metadata/typedef_generic_types_in_arguments_and_bounds.dart.strong.transformed.expect
@@ -13,13 +13,13 @@
     : super self::A::•()
     ;
 }
-class C<Z extends <Y extends core::Object? = dynamic>(Y%) → dynamic = <Y extends core::Object? = dynamic>(Y%) → dynamic> extends core::Object {
+class C<Z extends <Y extends core::Object? = dynamic>(Y%) → dynamic> extends core::Object {
   synthetic constructor •() → self::C<self::C::Z>
     : super core::Object::•()
     ;
 }
 static method foo(self::A<<Y extends core::Object? = dynamic>(Y%) → dynamic> x) → self::A<<Y extends core::Object? = dynamic>(Y%) → dynamic>
   return throw 42;
-static method bar<V extends <Y extends core::Object? = dynamic>(Y%) → dynamic = <Y extends core::Object? = dynamic>(Y%) → dynamic>() → dynamic
+static method bar<V extends <Y extends core::Object? = dynamic>(Y%) → dynamic>() → dynamic
   return throw 42;
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/generic_metadata/typedef_generic_types_in_arguments_and_bounds.dart.weak.expect b/pkg/front_end/testcases/generic_metadata/typedef_generic_types_in_arguments_and_bounds.dart.weak.expect
index dd20ce4..e853954 100644
--- a/pkg/front_end/testcases/generic_metadata/typedef_generic_types_in_arguments_and_bounds.dart.weak.expect
+++ b/pkg/front_end/testcases/generic_metadata/typedef_generic_types_in_arguments_and_bounds.dart.weak.expect
@@ -13,13 +13,13 @@
     : super self::A::•()
     ;
 }
-class C<Z extends <Y extends core::Object? = dynamic>(Y%) → dynamic = <Y extends core::Object? = dynamic>(Y%) → dynamic> extends core::Object {
+class C<Z extends <Y extends core::Object? = dynamic>(Y%) → dynamic> extends core::Object {
   synthetic constructor •() → self::C<self::C::Z>
     : super core::Object::•()
     ;
 }
 static method foo(self::A<<Y extends core::Object? = dynamic>(Y%) → dynamic> x) → self::A<<Y extends core::Object? = dynamic>(Y%) → dynamic>
   return throw 42;
-static method bar<V extends <Y extends core::Object? = dynamic>(Y%) → dynamic = <Y extends core::Object? = dynamic>(Y%) → dynamic>() → dynamic
+static method bar<V extends <Y extends core::Object? = dynamic>(Y%) → dynamic>() → dynamic
   return throw 42;
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/generic_metadata/typedef_generic_types_in_arguments_and_bounds.dart.weak.outline.expect b/pkg/front_end/testcases/generic_metadata/typedef_generic_types_in_arguments_and_bounds.dart.weak.outline.expect
index 1fbe2f1..7c86aa6 100644
--- a/pkg/front_end/testcases/generic_metadata/typedef_generic_types_in_arguments_and_bounds.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/generic_metadata/typedef_generic_types_in_arguments_and_bounds.dart.weak.outline.expect
@@ -11,13 +11,13 @@
   synthetic constructor •() → self::B
     ;
 }
-class C<Z extends <Y extends core::Object? = dynamic>(Y%) → dynamic = <Y extends core::Object? = dynamic>(Y%) → dynamic> extends core::Object {
+class C<Z extends <Y extends core::Object? = dynamic>(Y%) → dynamic> extends core::Object {
   synthetic constructor •() → self::C<self::C::Z>
     ;
 }
 static method foo(self::A<<Y extends core::Object? = dynamic>(Y%) → dynamic> x) → self::A<<Y extends core::Object? = dynamic>(Y%) → dynamic>
   ;
-static method bar<V extends <Y extends core::Object? = dynamic>(Y%) → dynamic = <Y extends core::Object? = dynamic>(Y%) → dynamic>() → dynamic
+static method bar<V extends <Y extends core::Object? = dynamic>(Y%) → dynamic>() → dynamic
   ;
 static method main() → dynamic
   ;
diff --git a/pkg/front_end/testcases/generic_metadata/typedef_generic_types_in_arguments_and_bounds.dart.weak.transformed.expect b/pkg/front_end/testcases/generic_metadata/typedef_generic_types_in_arguments_and_bounds.dart.weak.transformed.expect
index dd20ce4..e853954 100644
--- a/pkg/front_end/testcases/generic_metadata/typedef_generic_types_in_arguments_and_bounds.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/generic_metadata/typedef_generic_types_in_arguments_and_bounds.dart.weak.transformed.expect
@@ -13,13 +13,13 @@
     : super self::A::•()
     ;
 }
-class C<Z extends <Y extends core::Object? = dynamic>(Y%) → dynamic = <Y extends core::Object? = dynamic>(Y%) → dynamic> extends core::Object {
+class C<Z extends <Y extends core::Object? = dynamic>(Y%) → dynamic> extends core::Object {
   synthetic constructor •() → self::C<self::C::Z>
     : super core::Object::•()
     ;
 }
 static method foo(self::A<<Y extends core::Object? = dynamic>(Y%) → dynamic> x) → self::A<<Y extends core::Object? = dynamic>(Y%) → dynamic>
   return throw 42;
-static method bar<V extends <Y extends core::Object? = dynamic>(Y%) → dynamic = <Y extends core::Object? = dynamic>(Y%) → dynamic>() → dynamic
+static method bar<V extends <Y extends core::Object? = dynamic>(Y%) → dynamic>() → dynamic
   return throw 42;
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/incremental/flutter_issue_66122.yaml.world.1.expect b/pkg/front_end/testcases/incremental/flutter_issue_66122.yaml.world.1.expect
index 83dfce6..596001e 100644
--- a/pkg/front_end/testcases/incremental/flutter_issue_66122.yaml.world.1.expect
+++ b/pkg/front_end/testcases/incremental/flutter_issue_66122.yaml.world.1.expect
@@ -3,7 +3,7 @@
 
   import "package:flutter/framework.dart";
 
-  abstract class AfterLayoutMixin<T extends fra::StatefulWidget* = fra::StatefulWidget*> extends fra::State<aft::AfterLayoutMixin::T*> /*isMixinDeclaration*/  {
+  abstract class AfterLayoutMixin<T extends fra::StatefulWidget*> extends fra::State<aft::AfterLayoutMixin::T*> /*isMixinDeclaration*/  {
     abstract member-signature get _widget() → aft::AfterLayoutMixin::T*; -> fra::State::_widget
     abstract member-signature set _widget(generic-covariant-impl aft::AfterLayoutMixin::T* value) → void; -> fra::State::_widget
     abstract member-signature method toString() → dart.core::String*; -> fra::_State&Object&Diagnosticable::toString
@@ -27,7 +27,7 @@
     mixin-super-stub method toString() → dart.core::String
       return super.{fra::Diagnosticable::toString}();
   }
-  abstract class State<T extends fra::StatefulWidget = fra::StatefulWidget> extends fra::_State&Object&Diagnosticable {
+  abstract class State<T extends fra::StatefulWidget> extends fra::_State&Object&Diagnosticable {
     generic-covariant-impl field fra::State::T? _widget = null;
     synthetic constructor •() → fra::State<fra::State::T>
       : super fra::_State&Object&Diagnosticable::•()
diff --git a/pkg/front_end/testcases/incremental/flutter_issue_66122.yaml.world.2.expect b/pkg/front_end/testcases/incremental/flutter_issue_66122.yaml.world.2.expect
index 7d7406e..f1cc6fa 100644
--- a/pkg/front_end/testcases/incremental/flutter_issue_66122.yaml.world.2.expect
+++ b/pkg/front_end/testcases/incremental/flutter_issue_66122.yaml.world.2.expect
@@ -3,7 +3,7 @@
 
   import "package:flutter/framework.dart";
 
-  abstract class AfterLayoutMixin<T extends fra::StatefulWidget* = fra::StatefulWidget*> extends fra::State<aft::AfterLayoutMixin::T*> /*isMixinDeclaration*/  {
+  abstract class AfterLayoutMixin<T extends fra::StatefulWidget*> extends fra::State<aft::AfterLayoutMixin::T*> /*isMixinDeclaration*/  {
     abstract member-signature get _widget() → aft::AfterLayoutMixin::T*; -> fra::State::_widget
     abstract member-signature set _widget(generic-covariant-impl aft::AfterLayoutMixin::T* value) → void; -> fra::State::_widget
     abstract member-signature method toString() → dart.core::String*; -> fra::_State&Object&Diagnosticable::toString
@@ -27,7 +27,7 @@
     mixin-super-stub method toString() → dart.core::String
       return super.{fra::Diagnosticable::toString}();
   }
-  abstract class State<T extends fra::StatefulWidget = fra::StatefulWidget> extends fra::_State&Object&Diagnosticable {
+  abstract class State<T extends fra::StatefulWidget> extends fra::_State&Object&Diagnosticable {
     generic-covariant-impl field fra::State::T? _widget = null;
     synthetic constructor •() → fra::State<fra::State::T>
       : super fra::_State&Object&Diagnosticable::•()
diff --git a/pkg/front_end/testcases/incremental/reissue_errors_6.yaml.world.1.expect b/pkg/front_end/testcases/incremental/reissue_errors_6.yaml.world.1.expect
index f12602b..3d2f012 100644
--- a/pkg/front_end/testcases/incremental/reissue_errors_6.yaml.world.1.expect
+++ b/pkg/front_end/testcases/incremental/reissue_errors_6.yaml.world.1.expect
@@ -12,7 +12,7 @@
 //                     ^^^
 //
 
-  class Bar<X extends invalid-type = invalid-type> extends dart.core::Object {
+  class Bar<X extends invalid-type> extends dart.core::Object {
     synthetic constructor •() → lib::Bar<lib::Bar::X*>*
       : super dart.core::Object::•()
       ;
@@ -32,7 +32,7 @@
 
   import "org-dartlang-test:///lib.dart";
 
-  class Foo<X extends lib::Bar<invalid-type>* = lib::Bar<invalid-type>*> extends dart.core::Object {
+  class Foo<X extends lib::Bar<invalid-type>*> extends dart.core::Object {
     synthetic constructor •() → main::Foo<main::Foo::X*>*
       : super dart.core::Object::•()
       ;
diff --git a/pkg/front_end/testcases/incremental/reissue_errors_6.yaml.world.2.expect b/pkg/front_end/testcases/incremental/reissue_errors_6.yaml.world.2.expect
index 5ad635e..4033273 100644
--- a/pkg/front_end/testcases/incremental/reissue_errors_6.yaml.world.2.expect
+++ b/pkg/front_end/testcases/incremental/reissue_errors_6.yaml.world.2.expect
@@ -12,7 +12,7 @@
 //                     ^^^
 //
 
-  class Bar<X extends invalid-type = invalid-type> extends dart.core::Object {
+  class Bar<X extends invalid-type> extends dart.core::Object {
     synthetic constructor •() → lib::Bar<lib::Bar::X*>*
       : super dart.core::Object::•()
       ;
diff --git a/pkg/front_end/testcases/incremental/reissue_errors_6.yaml.world.3.expect b/pkg/front_end/testcases/incremental/reissue_errors_6.yaml.world.3.expect
index fab0774..3c1d034 100644
--- a/pkg/front_end/testcases/incremental/reissue_errors_6.yaml.world.3.expect
+++ b/pkg/front_end/testcases/incremental/reissue_errors_6.yaml.world.3.expect
@@ -3,7 +3,7 @@
 
   import "org-dartlang-test:///main.dart";
 
-  class Bar<X extends main::Foo<Null>* = main::Foo<Null>*> extends dart.core::Object {
+  class Bar<X extends main::Foo<Null>*> extends dart.core::Object {
     synthetic constructor •() → lib::Bar<lib::Bar::X*>*
       : super dart.core::Object::•()
       ;
@@ -23,7 +23,7 @@
 
   import "org-dartlang-test:///lib.dart";
 
-  class Foo<X extends lib::Bar<main::Foo<Null>*>* = lib::Bar<main::Foo<Null>*>*> extends dart.core::Object {
+  class Foo<X extends lib::Bar<main::Foo<Null>*>*> extends dart.core::Object {
     synthetic constructor •() → main::Foo<main::Foo::X*>*
       : super dart.core::Object::•()
       ;
diff --git a/pkg/front_end/testcases/inference/constructors_downwards_with_constraint.dart.weak.expect b/pkg/front_end/testcases/inference/constructors_downwards_with_constraint.dart.weak.expect
index dc47257..7a1c1c0 100644
--- a/pkg/front_end/testcases/inference/constructors_downwards_with_constraint.dart.weak.expect
+++ b/pkg/front_end/testcases/inference/constructors_downwards_with_constraint.dart.weak.expect
@@ -22,7 +22,7 @@
     : super self::A::•()
     ;
 }
-class Foo<T extends self::A* = self::A*> extends core::Object {
+class Foo<T extends self::A*> extends core::Object {
   synthetic constructor •() → self::Foo<self::Foo::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/inference/constructors_downwards_with_constraint.dart.weak.outline.expect b/pkg/front_end/testcases/inference/constructors_downwards_with_constraint.dart.weak.outline.expect
index 20ef2cd..3f5622c 100644
--- a/pkg/front_end/testcases/inference/constructors_downwards_with_constraint.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/inference/constructors_downwards_with_constraint.dart.weak.outline.expect
@@ -20,7 +20,7 @@
   synthetic constructor •() → self::B*
     ;
 }
-class Foo<T extends self::A* = self::A*> extends core::Object {
+class Foo<T extends self::A*> extends core::Object {
   synthetic constructor •() → self::Foo<self::Foo::T*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/inference/constructors_downwards_with_constraint.dart.weak.transformed.expect b/pkg/front_end/testcases/inference/constructors_downwards_with_constraint.dart.weak.transformed.expect
index dc47257..7a1c1c0 100644
--- a/pkg/front_end/testcases/inference/constructors_downwards_with_constraint.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/inference/constructors_downwards_with_constraint.dart.weak.transformed.expect
@@ -22,7 +22,7 @@
     : super self::A::•()
     ;
 }
-class Foo<T extends self::A* = self::A*> extends core::Object {
+class Foo<T extends self::A*> extends core::Object {
   synthetic constructor •() → self::Foo<self::Foo::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/inference/constructors_infer_from_arguments_argument_not_assignable.dart.weak.expect b/pkg/front_end/testcases/inference/constructors_infer_from_arguments_argument_not_assignable.dart.weak.expect
index 8445171..706d512 100644
--- a/pkg/front_end/testcases/inference/constructors_infer_from_arguments_argument_not_assignable.dart.weak.expect
+++ b/pkg/front_end/testcases/inference/constructors_infer_from_arguments_argument_not_assignable.dart.weak.expect
@@ -41,7 +41,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class C<T extends self::A* = self::A*> extends core::Object {
+class C<T extends self::A*> extends core::Object {
   constructor •(() →* self::C::T* f) → self::C<self::C::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/inference/constructors_infer_from_arguments_argument_not_assignable.dart.weak.outline.expect b/pkg/front_end/testcases/inference/constructors_infer_from_arguments_argument_not_assignable.dart.weak.outline.expect
index a91a655f..9a32b9b 100644
--- a/pkg/front_end/testcases/inference/constructors_infer_from_arguments_argument_not_assignable.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/inference/constructors_infer_from_arguments_argument_not_assignable.dart.weak.outline.expect
@@ -17,7 +17,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class C<T extends self::A* = self::A*> extends core::Object {
+class C<T extends self::A*> extends core::Object {
   constructor •(() →* self::C::T* f) → self::C<self::C::T*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/inference/constructors_infer_from_arguments_const_with_upper_bound.dart.weak.expect b/pkg/front_end/testcases/inference/constructors_infer_from_arguments_const_with_upper_bound.dart.weak.expect
index f64a716..c79ff6d 100644
--- a/pkg/front_end/testcases/inference/constructors_infer_from_arguments_const_with_upper_bound.dart.weak.expect
+++ b/pkg/front_end/testcases/inference/constructors_infer_from_arguments_const_with_upper_bound.dart.weak.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class C<T extends core::num* = core::num*> extends core::Object /*hasConstConstructor*/  {
+class C<T extends core::num*> extends core::Object /*hasConstConstructor*/  {
   final field self::C::T* x;
   const constructor •(self::C::T* x) → self::C<self::C::T*>*
     : self::C::x = x, super core::Object::•()
@@ -18,7 +18,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class D<T extends core::num* = core::num*> extends core::Object /*hasConstConstructor*/  {
+class D<T extends core::num*> extends core::Object /*hasConstConstructor*/  {
   const constructor •() → self::D<self::D::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/inference/constructors_infer_from_arguments_const_with_upper_bound.dart.weak.outline.expect b/pkg/front_end/testcases/inference/constructors_infer_from_arguments_const_with_upper_bound.dart.weak.outline.expect
index 11e4ec2..0b30da0d 100644
--- a/pkg/front_end/testcases/inference/constructors_infer_from_arguments_const_with_upper_bound.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/inference/constructors_infer_from_arguments_const_with_upper_bound.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class C<T extends core::num* = core::num*> extends core::Object /*hasConstConstructor*/  {
+class C<T extends core::num*> extends core::Object /*hasConstConstructor*/  {
   final field self::C::T* x;
   const constructor •(self::C::T* x) → self::C<self::C::T*>*
     : self::C::x = x, super core::Object::•()
@@ -18,7 +18,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class D<T extends core::num* = core::num*> extends core::Object /*hasConstConstructor*/  {
+class D<T extends core::num*> extends core::Object /*hasConstConstructor*/  {
   const constructor •() → self::D<self::D::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/inference/constructors_infer_from_arguments_const_with_upper_bound.dart.weak.transformed.expect b/pkg/front_end/testcases/inference/constructors_infer_from_arguments_const_with_upper_bound.dart.weak.transformed.expect
index f64a716..c79ff6d 100644
--- a/pkg/front_end/testcases/inference/constructors_infer_from_arguments_const_with_upper_bound.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/inference/constructors_infer_from_arguments_const_with_upper_bound.dart.weak.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class C<T extends core::num* = core::num*> extends core::Object /*hasConstConstructor*/  {
+class C<T extends core::num*> extends core::Object /*hasConstConstructor*/  {
   final field self::C::T* x;
   const constructor •(self::C::T* x) → self::C<self::C::T*>*
     : self::C::x = x, super core::Object::•()
@@ -18,7 +18,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class D<T extends core::num* = core::num*> extends core::Object /*hasConstConstructor*/  {
+class D<T extends core::num*> extends core::Object /*hasConstConstructor*/  {
   const constructor •() → self::D<self::D::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/inference/generic_methods_correctly_recognize_generic_upper_bound.dart.weak.expect b/pkg/front_end/testcases/inference/generic_methods_correctly_recognize_generic_upper_bound.dart.weak.expect
index b512907..3569bc6 100644
--- a/pkg/front_end/testcases/inference/generic_methods_correctly_recognize_generic_upper_bound.dart.weak.expect
+++ b/pkg/front_end/testcases/inference/generic_methods_correctly_recognize_generic_upper_bound.dart.weak.expect
@@ -11,11 +11,11 @@
 import self as self;
 import "dart:core" as core;
 
-class Foo<T extends core::Pattern* = core::Pattern*> extends core::Object {
+class Foo<T extends core::Pattern*> extends core::Object {
   synthetic constructor •() → self::Foo<self::Foo::T*>*
     : super core::Object::•()
     ;
-  method method<generic-covariant-impl U extends self::Foo::T* = self::Foo::T*>(self::Foo::method::U* u) → self::Foo::method::U*
+  method method<generic-covariant-impl U extends self::Foo::T*>(self::Foo::method::U* u) → self::Foo::method::U*
     return u;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
diff --git a/pkg/front_end/testcases/inference/generic_methods_correctly_recognize_generic_upper_bound.dart.weak.outline.expect b/pkg/front_end/testcases/inference/generic_methods_correctly_recognize_generic_upper_bound.dart.weak.outline.expect
index d2565cf..981c3c1 100644
--- a/pkg/front_end/testcases/inference/generic_methods_correctly_recognize_generic_upper_bound.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/inference/generic_methods_correctly_recognize_generic_upper_bound.dart.weak.outline.expect
@@ -2,10 +2,10 @@
 import self as self;
 import "dart:core" as core;
 
-class Foo<T extends core::Pattern* = core::Pattern*> extends core::Object {
+class Foo<T extends core::Pattern*> extends core::Object {
   synthetic constructor •() → self::Foo<self::Foo::T*>*
     ;
-  method method<generic-covariant-impl U extends self::Foo::T* = self::Foo::T*>(self::Foo::method::U* u) → self::Foo::method::U*
+  method method<generic-covariant-impl U extends self::Foo::T*>(self::Foo::method::U* u) → self::Foo::method::U*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
diff --git a/pkg/front_end/testcases/inference/generic_methods_infer_generic_instantiation.dart.weak.expect b/pkg/front_end/testcases/inference/generic_methods_infer_generic_instantiation.dart.weak.expect
index 91a24d9..527c4b0 100644
--- a/pkg/front_end/testcases/inference/generic_methods_infer_generic_instantiation.dart.weak.expect
+++ b/pkg/front_end/testcases/inference/generic_methods_infer_generic_instantiation.dart.weak.expect
@@ -36,7 +36,7 @@
   synthetic constructor •() → self::C*
     : super core::Object::•()
     ;
-  method m<T extends core::num* = core::num*>(self::C::m::T* x, self::C::m::T* y) → self::C::m::T*
+  method m<T extends core::num*>(self::C::m::T* x, self::C::m::T* y) → self::C::m::T*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
diff --git a/pkg/front_end/testcases/inference/generic_methods_infer_generic_instantiation.dart.weak.outline.expect b/pkg/front_end/testcases/inference/generic_methods_infer_generic_instantiation.dart.weak.outline.expect
index 4f1f11c..0c12d64 100644
--- a/pkg/front_end/testcases/inference/generic_methods_infer_generic_instantiation.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/inference/generic_methods_infer_generic_instantiation.dart.weak.outline.expect
@@ -8,7 +8,7 @@
 class C extends core::Object {
   synthetic constructor •() → self::C*
     ;
-  method m<T extends core::num* = core::num*>(self::C::m::T* x, self::C::m::T* y) → self::C::m::T*
+  method m<T extends core::num*>(self::C::m::T* x, self::C::m::T* y) → self::C::m::T*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
diff --git a/pkg/front_end/testcases/inference/generic_methods_infer_generic_instantiation.dart.weak.transformed.expect b/pkg/front_end/testcases/inference/generic_methods_infer_generic_instantiation.dart.weak.transformed.expect
index a5a6c34..3783f0e 100644
--- a/pkg/front_end/testcases/inference/generic_methods_infer_generic_instantiation.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/inference/generic_methods_infer_generic_instantiation.dart.weak.transformed.expect
@@ -36,7 +36,7 @@
   synthetic constructor •() → self::C*
     : super core::Object::•()
     ;
-  method m<T extends core::num* = core::num*>(self::C::m::T* x, self::C::m::T* y) → self::C::m::T*
+  method m<T extends core::num*>(self::C::m::T* x, self::C::m::T* y) → self::C::m::T*
     return null;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
diff --git a/pkg/front_end/testcases/inference/infer_types_on_loop_indices_for_each_loop.dart.weak.expect b/pkg/front_end/testcases/inference/infer_types_on_loop_indices_for_each_loop.dart.weak.expect
index 3cf3930..0b511ab 100644
--- a/pkg/front_end/testcases/inference/infer_types_on_loop_indices_for_each_loop.dart.weak.expect
+++ b/pkg/front_end/testcases/inference/infer_types_on_loop_indices_for_each_loop.dart.weak.expect
@@ -47,7 +47,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Bar<T extends core::Iterable<core::String*>* = core::Iterable<core::String*>*> extends core::Object {
+class Bar<T extends core::Iterable<core::String*>*> extends core::Object {
   synthetic constructor •() → self::Bar<self::Bar::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/inference/infer_types_on_loop_indices_for_each_loop.dart.weak.outline.expect b/pkg/front_end/testcases/inference/infer_types_on_loop_indices_for_each_loop.dart.weak.outline.expect
index fb24a4a..a8d39ff 100644
--- a/pkg/front_end/testcases/inference/infer_types_on_loop_indices_for_each_loop.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/inference/infer_types_on_loop_indices_for_each_loop.dart.weak.outline.expect
@@ -17,7 +17,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Bar<T extends core::Iterable<core::String*>* = core::Iterable<core::String*>*> extends core::Object {
+class Bar<T extends core::Iterable<core::String*>*> extends core::Object {
   synthetic constructor •() → self::Bar<self::Bar::T*>*
     ;
   method foo(generic-covariant-impl self::Bar::T* t) → void
diff --git a/pkg/front_end/testcases/inference/infer_types_on_loop_indices_for_each_loop.dart.weak.transformed.expect b/pkg/front_end/testcases/inference/infer_types_on_loop_indices_for_each_loop.dart.weak.transformed.expect
index 2b13c7f..37f2947 100644
--- a/pkg/front_end/testcases/inference/infer_types_on_loop_indices_for_each_loop.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/inference/infer_types_on_loop_indices_for_each_loop.dart.weak.transformed.expect
@@ -47,7 +47,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Bar<T extends core::Iterable<core::String*>* = core::Iterable<core::String*>*> extends core::Object {
+class Bar<T extends core::Iterable<core::String*>*> extends core::Object {
   synthetic constructor •() → self::Bar<self::Bar::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/inference/infer_types_on_loop_indices_for_each_loop_async.dart.weak.expect b/pkg/front_end/testcases/inference/infer_types_on_loop_indices_for_each_loop_async.dart.weak.expect
index 0c59f14..c01f6d8 100644
--- a/pkg/front_end/testcases/inference/infer_types_on_loop_indices_for_each_loop_async.dart.weak.expect
+++ b/pkg/front_end/testcases/inference/infer_types_on_loop_indices_for_each_loop_async.dart.weak.expect
@@ -50,7 +50,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Bar<T extends asy::Stream<core::String*>* = asy::Stream<core::String*>*> extends core::Object {
+class Bar<T extends asy::Stream<core::String*>*> extends core::Object {
   synthetic constructor •() → self::Bar<self::Bar::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/inference/infer_types_on_loop_indices_for_each_loop_async.dart.weak.outline.expect b/pkg/front_end/testcases/inference/infer_types_on_loop_indices_for_each_loop_async.dart.weak.outline.expect
index 98b90b7..3b83fec 100644
--- a/pkg/front_end/testcases/inference/infer_types_on_loop_indices_for_each_loop_async.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/inference/infer_types_on_loop_indices_for_each_loop_async.dart.weak.outline.expect
@@ -20,7 +20,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Bar<T extends asy::Stream<core::String*>* = asy::Stream<core::String*>*> extends core::Object {
+class Bar<T extends asy::Stream<core::String*>*> extends core::Object {
   synthetic constructor •() → self::Bar<self::Bar::T*>*
     ;
   method foo(generic-covariant-impl self::Bar::T* t) → dynamic async 
diff --git a/pkg/front_end/testcases/inference/infer_types_on_loop_indices_for_each_loop_async.dart.weak.transformed.expect b/pkg/front_end/testcases/inference/infer_types_on_loop_indices_for_each_loop_async.dart.weak.transformed.expect
index 2b08fb6..9b13665 100644
--- a/pkg/front_end/testcases/inference/infer_types_on_loop_indices_for_each_loop_async.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/inference/infer_types_on_loop_indices_for_each_loop_async.dart.weak.transformed.expect
@@ -51,7 +51,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Bar<T extends asy::Stream<core::String*>* = asy::Stream<core::String*>*> extends core::Object {
+class Bar<T extends asy::Stream<core::String*>*> extends core::Object {
   synthetic constructor •() → self::Bar<self::Bar::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_has_bound_defined_after.dart.weak.expect b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_has_bound_defined_after.dart.weak.expect
index 8b892ed..0fb60dc 100644
--- a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_has_bound_defined_after.dart.weak.expect
+++ b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_has_bound_defined_after.dart.weak.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class B<T extends self::A<core::int*>* = self::A<core::int*>*> extends core::Object {
+class B<T extends self::A<core::int*>*> extends core::Object {
   synthetic constructor •() → self::B<self::B::T*>*
     : super core::Object::•()
     ;
@@ -17,7 +17,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class A<T extends core::int* = core::int*> extends core::Object {
+class A<T extends core::int*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_has_bound_defined_after.dart.weak.outline.expect b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_has_bound_defined_after.dart.weak.outline.expect
index d2cbeee..e676290 100644
--- a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_has_bound_defined_after.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_has_bound_defined_after.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class B<T extends self::A<core::int*>* = self::A<core::int*>*> extends core::Object {
+class B<T extends self::A<core::int*>*> extends core::Object {
   synthetic constructor •() → self::B<self::B::T*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
@@ -16,7 +16,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class A<T extends core::int* = core::int*> extends core::Object {
+class A<T extends core::int*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_has_bound_defined_after.dart.weak.transformed.expect b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_has_bound_defined_after.dart.weak.transformed.expect
index 8b892ed..0fb60dc 100644
--- a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_has_bound_defined_after.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_has_bound_defined_after.dart.weak.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class B<T extends self::A<core::int*>* = self::A<core::int*>*> extends core::Object {
+class B<T extends self::A<core::int*>*> extends core::Object {
   synthetic constructor •() → self::B<self::B::T*>*
     : super core::Object::•()
     ;
@@ -17,7 +17,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class A<T extends core::int* = core::int*> extends core::Object {
+class A<T extends core::int*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_has_bound_defined_before.dart.weak.expect b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_has_bound_defined_before.dart.weak.expect
index 7654a70..0612d0f 100644
--- a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_has_bound_defined_before.dart.weak.expect
+++ b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_has_bound_defined_before.dart.weak.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::int* = core::int*> extends core::Object {
+class A<T extends core::int*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     : super core::Object::•()
     ;
@@ -17,7 +17,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class B<T extends self::A<core::int*>* = self::A<core::int*>*> extends core::Object {
+class B<T extends self::A<core::int*>*> extends core::Object {
   synthetic constructor •() → self::B<self::B::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_has_bound_defined_before.dart.weak.outline.expect b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_has_bound_defined_before.dart.weak.outline.expect
index 6aea523..8a8c77b 100644
--- a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_has_bound_defined_before.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_has_bound_defined_before.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::int* = core::int*> extends core::Object {
+class A<T extends core::int*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
@@ -16,7 +16,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class B<T extends self::A<core::int*>* = self::A<core::int*>*> extends core::Object {
+class B<T extends self::A<core::int*>*> extends core::Object {
   synthetic constructor •() → self::B<self::B::T*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_has_bound_defined_before.dart.weak.transformed.expect b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_has_bound_defined_before.dart.weak.transformed.expect
index 7654a70..0612d0f 100644
--- a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_has_bound_defined_before.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_has_bound_defined_before.dart.weak.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::int* = core::int*> extends core::Object {
+class A<T extends core::int*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     : super core::Object::•()
     ;
@@ -17,7 +17,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class B<T extends self::A<core::int*>* = self::A<core::int*>*> extends core::Object {
+class B<T extends self::A<core::int*>*> extends core::Object {
   synthetic constructor •() → self::B<self::B::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_no_bound.dart.weak.expect b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_no_bound.dart.weak.expect
index b9fff9c..731ae28 100644
--- a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_no_bound.dart.weak.expect
+++ b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_no_bound.dart.weak.expect
@@ -17,7 +17,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class B<T extends self::A<dynamic>* = self::A<dynamic>*> extends core::Object {
+class B<T extends self::A<dynamic>*> extends core::Object {
   synthetic constructor •() → self::B<self::B::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_no_bound.dart.weak.outline.expect b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_no_bound.dart.weak.outline.expect
index ca700cd..f7e09d3 100644
--- a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_no_bound.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_no_bound.dart.weak.outline.expect
@@ -16,7 +16,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class B<T extends self::A<dynamic>* = self::A<dynamic>*> extends core::Object {
+class B<T extends self::A<dynamic>*> extends core::Object {
   synthetic constructor •() → self::B<self::B::T*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_no_bound.dart.weak.transformed.expect b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_no_bound.dart.weak.transformed.expect
index b9fff9c..731ae28 100644
--- a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_no_bound.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic2_no_bound.dart.weak.transformed.expect
@@ -17,7 +17,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class B<T extends self::A<dynamic>* = self::A<dynamic>*> extends core::Object {
+class B<T extends self::A<dynamic>*> extends core::Object {
   synthetic constructor •() → self::B<self::B::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic_has_bound_defined_after.dart.weak.expect b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic_has_bound_defined_after.dart.weak.expect
index 002ee58..09072c4 100644
--- a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic_has_bound_defined_after.dart.weak.expect
+++ b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic_has_bound_defined_after.dart.weak.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::int* = core::int*> extends core::Object {
+class A<T extends core::int*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic_has_bound_defined_after.dart.weak.outline.expect b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic_has_bound_defined_after.dart.weak.outline.expect
index 0757181..5cb5fd6 100644
--- a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic_has_bound_defined_after.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic_has_bound_defined_after.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::int* = core::int*> extends core::Object {
+class A<T extends core::int*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic_has_bound_defined_after.dart.weak.transformed.expect b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic_has_bound_defined_after.dart.weak.transformed.expect
index 002ee58..09072c4 100644
--- a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic_has_bound_defined_after.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic_has_bound_defined_after.dart.weak.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::int* = core::int*> extends core::Object {
+class A<T extends core::int*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic_has_bound_defined_before.dart.weak.expect b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic_has_bound_defined_before.dart.weak.expect
index 002ee58..09072c4 100644
--- a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic_has_bound_defined_before.dart.weak.expect
+++ b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic_has_bound_defined_before.dart.weak.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::int* = core::int*> extends core::Object {
+class A<T extends core::int*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic_has_bound_defined_before.dart.weak.outline.expect b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic_has_bound_defined_before.dart.weak.outline.expect
index 0757181..5cb5fd6 100644
--- a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic_has_bound_defined_before.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic_has_bound_defined_before.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::int* = core::int*> extends core::Object {
+class A<T extends core::int*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic_has_bound_defined_before.dart.weak.transformed.expect b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic_has_bound_defined_before.dart.weak.transformed.expect
index 002ee58..09072c4 100644
--- a/pkg/front_end/testcases/inference/instantiate_to_bounds_generic_has_bound_defined_before.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/inference/instantiate_to_bounds_generic_has_bound_defined_before.dart.weak.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::int* = core::int*> extends core::Object {
+class A<T extends core::int*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/inference/instantiate_to_bounds_invoke_constructor_type_args_exact.dart.weak.expect b/pkg/front_end/testcases/inference/instantiate_to_bounds_invoke_constructor_type_args_exact.dart.weak.expect
index f2d000e..1fb9971 100644
--- a/pkg/front_end/testcases/inference/instantiate_to_bounds_invoke_constructor_type_args_exact.dart.weak.expect
+++ b/pkg/front_end/testcases/inference/instantiate_to_bounds_invoke_constructor_type_args_exact.dart.weak.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class C<T extends core::num* = core::num*> extends core::Object {
+class C<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::C<self::C::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/inference/instantiate_to_bounds_invoke_constructor_type_args_exact.dart.weak.outline.expect b/pkg/front_end/testcases/inference/instantiate_to_bounds_invoke_constructor_type_args_exact.dart.weak.outline.expect
index a968144..1338660 100644
--- a/pkg/front_end/testcases/inference/instantiate_to_bounds_invoke_constructor_type_args_exact.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/inference/instantiate_to_bounds_invoke_constructor_type_args_exact.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class C<T extends core::num* = core::num*> extends core::Object {
+class C<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::C<self::C::T*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/inference/instantiate_to_bounds_invoke_constructor_type_args_exact.dart.weak.transformed.expect b/pkg/front_end/testcases/inference/instantiate_to_bounds_invoke_constructor_type_args_exact.dart.weak.transformed.expect
index f2d000e..1fb9971 100644
--- a/pkg/front_end/testcases/inference/instantiate_to_bounds_invoke_constructor_type_args_exact.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/inference/instantiate_to_bounds_invoke_constructor_type_args_exact.dart.weak.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class C<T extends core::num* = core::num*> extends core::Object {
+class C<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::C<self::C::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/inference/instantiate_to_bounds_not_generic.dart.weak.expect b/pkg/front_end/testcases/inference/instantiate_to_bounds_not_generic.dart.weak.expect
index 774152a..6bd9194 100644
--- a/pkg/front_end/testcases/inference/instantiate_to_bounds_not_generic.dart.weak.expect
+++ b/pkg/front_end/testcases/inference/instantiate_to_bounds_not_generic.dart.weak.expect
@@ -17,7 +17,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class B<T extends self::A* = self::A*> extends core::Object {
+class B<T extends self::A*> extends core::Object {
   synthetic constructor •() → self::B<self::B::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/inference/instantiate_to_bounds_not_generic.dart.weak.outline.expect b/pkg/front_end/testcases/inference/instantiate_to_bounds_not_generic.dart.weak.outline.expect
index 2eff5be..ef0a99a 100644
--- a/pkg/front_end/testcases/inference/instantiate_to_bounds_not_generic.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/inference/instantiate_to_bounds_not_generic.dart.weak.outline.expect
@@ -16,7 +16,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class B<T extends self::A* = self::A*> extends core::Object {
+class B<T extends self::A*> extends core::Object {
   synthetic constructor •() → self::B<self::B::T*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/inference/instantiate_to_bounds_not_generic.dart.weak.transformed.expect b/pkg/front_end/testcases/inference/instantiate_to_bounds_not_generic.dart.weak.transformed.expect
index 774152a..6bd9194 100644
--- a/pkg/front_end/testcases/inference/instantiate_to_bounds_not_generic.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/inference/instantiate_to_bounds_not_generic.dart.weak.transformed.expect
@@ -17,7 +17,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class B<T extends self::A* = self::A*> extends core::Object {
+class B<T extends self::A*> extends core::Object {
   synthetic constructor •() → self::B<self::B::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/inference/mixin_inference_instantiate_to_bounds_1.dart.weak.expect b/pkg/front_end/testcases/inference/mixin_inference_instantiate_to_bounds_1.dart.weak.expect
index 545ce1b..ce1b438 100644
--- a/pkg/front_end/testcases/inference/mixin_inference_instantiate_to_bounds_1.dart.weak.expect
+++ b/pkg/front_end/testcases/inference/mixin_inference_instantiate_to_bounds_1.dart.weak.expect
@@ -17,7 +17,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class M0<X extends core::Object* = dynamic, Y extends core::String* = core::String*> extends self::I<self::M0::X*> {
+class M0<X extends core::Object* = dynamic, Y extends core::String*> extends self::I<self::M0::X*> {
   synthetic constructor •() → self::M0<self::M0::X*, self::M0::Y*>*
     : super self::I::•()
     ;
diff --git a/pkg/front_end/testcases/inference/mixin_inference_instantiate_to_bounds_1.dart.weak.outline.expect b/pkg/front_end/testcases/inference/mixin_inference_instantiate_to_bounds_1.dart.weak.outline.expect
index 239c31f..d73c867 100644
--- a/pkg/front_end/testcases/inference/mixin_inference_instantiate_to_bounds_1.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/inference/mixin_inference_instantiate_to_bounds_1.dart.weak.outline.expect
@@ -16,7 +16,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class M0<X extends core::Object* = dynamic, Y extends core::String* = core::String*> extends self::I<self::M0::X*> {
+class M0<X extends core::Object* = dynamic, Y extends core::String*> extends self::I<self::M0::X*> {
   synthetic constructor •() → self::M0<self::M0::X*, self::M0::Y*>*
     ;
 }
diff --git a/pkg/front_end/testcases/inference/mixin_inference_instantiate_to_bounds_1.dart.weak.transformed.expect b/pkg/front_end/testcases/inference/mixin_inference_instantiate_to_bounds_1.dart.weak.transformed.expect
index ad6db98..0ac49c5 100644
--- a/pkg/front_end/testcases/inference/mixin_inference_instantiate_to_bounds_1.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/inference/mixin_inference_instantiate_to_bounds_1.dart.weak.transformed.expect
@@ -17,7 +17,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class M0<X extends core::Object* = dynamic, Y extends core::String* = core::String*> extends self::I<self::M0::X*> {
+class M0<X extends core::Object* = dynamic, Y extends core::String*> extends self::I<self::M0::X*> {
   synthetic constructor •() → self::M0<self::M0::X*, self::M0::Y*>*
     : super self::I::•()
     ;
diff --git a/pkg/front_end/testcases/inference/mixin_inference_instantiate_to_bounds_4.dart.weak.expect b/pkg/front_end/testcases/inference/mixin_inference_instantiate_to_bounds_4.dart.weak.expect
index f7381da..4493630 100644
--- a/pkg/front_end/testcases/inference/mixin_inference_instantiate_to_bounds_4.dart.weak.expect
+++ b/pkg/front_end/testcases/inference/mixin_inference_instantiate_to_bounds_4.dart.weak.expect
@@ -17,7 +17,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class M0<X extends core::Object* = dynamic, Y extends ({name: core::String*}) →* void = ({name: core::String*}) →* void> extends self::I<self::M0::X*> {
+class M0<X extends core::Object* = dynamic, Y extends ({name: core::String*}) →* void> extends self::I<self::M0::X*> {
   synthetic constructor •() → self::M0<self::M0::X*, self::M0::Y*>*
     : super self::I::•()
     ;
diff --git a/pkg/front_end/testcases/inference/mixin_inference_instantiate_to_bounds_4.dart.weak.outline.expect b/pkg/front_end/testcases/inference/mixin_inference_instantiate_to_bounds_4.dart.weak.outline.expect
index a94c66e..11c5048 100644
--- a/pkg/front_end/testcases/inference/mixin_inference_instantiate_to_bounds_4.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/inference/mixin_inference_instantiate_to_bounds_4.dart.weak.outline.expect
@@ -16,7 +16,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class M0<X extends core::Object* = dynamic, Y extends ({name: core::String*}) →* void = ({name: core::String*}) →* void> extends self::I<self::M0::X*> {
+class M0<X extends core::Object* = dynamic, Y extends ({name: core::String*}) →* void> extends self::I<self::M0::X*> {
   synthetic constructor •() → self::M0<self::M0::X*, self::M0::Y*>*
     ;
 }
diff --git a/pkg/front_end/testcases/inference/mixin_inference_instantiate_to_bounds_4.dart.weak.transformed.expect b/pkg/front_end/testcases/inference/mixin_inference_instantiate_to_bounds_4.dart.weak.transformed.expect
index 5237b52..73fbc15 100644
--- a/pkg/front_end/testcases/inference/mixin_inference_instantiate_to_bounds_4.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/inference/mixin_inference_instantiate_to_bounds_4.dart.weak.transformed.expect
@@ -17,7 +17,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class M0<X extends core::Object* = dynamic, Y extends ({name: core::String*}) →* void = ({name: core::String*}) →* void> extends self::I<self::M0::X*> {
+class M0<X extends core::Object* = dynamic, Y extends ({name: core::String*}) →* void> extends self::I<self::M0::X*> {
   synthetic constructor •() → self::M0<self::M0::X*, self::M0::Y*>*
     : super self::I::•()
     ;
diff --git a/pkg/front_end/testcases/inference/promote_bounds.dart.weak.expect b/pkg/front_end/testcases/inference/promote_bounds.dart.weak.expect
index 49660c2..2559222 100644
--- a/pkg/front_end/testcases/inference/promote_bounds.dart.weak.expect
+++ b/pkg/front_end/testcases/inference/promote_bounds.dart.weak.expect
@@ -24,7 +24,7 @@
     ;
   abstract method bar() → void;
 }
-static method f<T extends self::B* = self::B*>(self::f::T* a) → void {
+static method f<T extends self::B*>(self::f::T* a) → void {
   if(a is core::String*) {
     a.{self::B::foo}();
   }
diff --git a/pkg/front_end/testcases/inference/promote_bounds.dart.weak.outline.expect b/pkg/front_end/testcases/inference/promote_bounds.dart.weak.outline.expect
index 208ac22..870ed64 100644
--- a/pkg/front_end/testcases/inference/promote_bounds.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/inference/promote_bounds.dart.weak.outline.expect
@@ -22,7 +22,7 @@
     ;
   abstract method bar() → void;
 }
-static method f<T extends self::B* = self::B*>(self::f::T* a) → void
+static method f<T extends self::B*>(self::f::T* a) → void
   ;
 static method main() → dynamic
   ;
diff --git a/pkg/front_end/testcases/inference/promote_bounds.dart.weak.transformed.expect b/pkg/front_end/testcases/inference/promote_bounds.dart.weak.transformed.expect
index 49660c2..2559222 100644
--- a/pkg/front_end/testcases/inference/promote_bounds.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/inference/promote_bounds.dart.weak.transformed.expect
@@ -24,7 +24,7 @@
     ;
   abstract method bar() → void;
 }
-static method f<T extends self::B* = self::B*>(self::f::T* a) → void {
+static method f<T extends self::B*>(self::f::T* a) → void {
   if(a is core::String*) {
     a.{self::B::foo}();
   }
diff --git a/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_double.dart.weak.expect b/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_double.dart.weak.expect
index fe7230d..c6c59b5 100644
--- a/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_double.dart.weak.expect
+++ b/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_double.dart.weak.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class C<T extends core::num* = core::num*> extends core::Object {
+class C<T extends core::num*> extends core::Object {
   generic-covariant-impl field self::C::T* a = null;
   synthetic constructor •() → self::C<self::C::T*>*
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_double.dart.weak.outline.expect b/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_double.dart.weak.outline.expect
index 9075050..f6a0aba 100644
--- a/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_double.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_double.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class C<T extends core::num* = core::num*> extends core::Object {
+class C<T extends core::num*> extends core::Object {
   generic-covariant-impl field self::C::T* a;
   synthetic constructor •() → self::C<self::C::T*>*
     ;
diff --git a/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_double.dart.weak.transformed.expect b/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_double.dart.weak.transformed.expect
index 7f2b553..6560a3f 100644
--- a/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_double.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_double.dart.weak.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class C<T extends core::num* = core::num*> extends core::Object {
+class C<T extends core::num*> extends core::Object {
   generic-covariant-impl field self::C::T* a = null;
   synthetic constructor •() → self::C<self::C::T*>*
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_int.dart.weak.expect b/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_int.dart.weak.expect
index 3f1e661..729edd2 100644
--- a/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_int.dart.weak.expect
+++ b/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_int.dart.weak.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class C<T extends core::num* = core::num*> extends core::Object {
+class C<T extends core::num*> extends core::Object {
   generic-covariant-impl field self::C::T* a = null;
   synthetic constructor •() → self::C<self::C::T*>*
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_int.dart.weak.outline.expect b/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_int.dart.weak.outline.expect
index e5feef6..5781f2e 100644
--- a/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_int.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_int.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class C<T extends core::num* = core::num*> extends core::Object {
+class C<T extends core::num*> extends core::Object {
   generic-covariant-impl field self::C::T* a;
   synthetic constructor •() → self::C<self::C::T*>*
     ;
diff --git a/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_int.dart.weak.transformed.expect b/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_int.dart.weak.transformed.expect
index 3f1e661..729edd2 100644
--- a/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_int.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_int.dart.weak.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class C<T extends core::num* = core::num*> extends core::Object {
+class C<T extends core::num*> extends core::Object {
   generic-covariant-impl field self::C::T* a = null;
   synthetic constructor •() → self::C<self::C::T*>*
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_t.dart.weak.expect b/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_t.dart.weak.expect
index 1af3200..fb481ea 100644
--- a/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_t.dart.weak.expect
+++ b/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_t.dart.weak.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class C<T extends core::num* = core::num*> extends core::Object {
+class C<T extends core::num*> extends core::Object {
   generic-covariant-impl field self::C::T* a = null;
   synthetic constructor •() → self::C<self::C::T*>*
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_t.dart.weak.outline.expect b/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_t.dart.weak.outline.expect
index 48982ba..8b713df 100644
--- a/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_t.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_t.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class C<T extends core::num* = core::num*> extends core::Object {
+class C<T extends core::num*> extends core::Object {
   generic-covariant-impl field self::C::T* a;
   synthetic constructor •() → self::C<self::C::T*>*
     ;
diff --git a/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_t.dart.weak.transformed.expect b/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_t.dart.weak.transformed.expect
index 1af3200..fb481ea 100644
--- a/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_t.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/inference/refine_binary_expression_type_type_parameter_t_t.dart.weak.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class C<T extends core::num* = core::num*> extends core::Object {
+class C<T extends core::num*> extends core::Object {
   generic-covariant-impl field self::C::T* a = null;
   synthetic constructor •() → self::C<self::C::T*>*
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/instantiate_to_bound/all_steps.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/all_steps.dart.weak.expect
index b96266f..336e446 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/all_steps.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/all_steps.dart.weak.expect
@@ -32,7 +32,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class D<X extends self::B<self::D::X*, self::D::Y*>* = self::B<dynamic, dynamic>*, Y extends self::C<self::D::X*, self::D::Y*>* = self::C<dynamic, dynamic>*, Z extends (self::D::Y*) →* self::D::X* = (Null) →* self::B<dynamic, dynamic>*, W extends core::num* = core::num*> extends core::Object {
+class D<X extends self::B<self::D::X*, self::D::Y*>* = self::B<dynamic, dynamic>*, Y extends self::C<self::D::X*, self::D::Y*>* = self::C<dynamic, dynamic>*, Z extends (self::D::Y*) →* self::D::X* = (Null) →* self::B<dynamic, dynamic>*, W extends core::num*> extends core::Object {
   synthetic constructor •() → self::D<self::D::X*, self::D::Y*, self::D::Z*, self::D::W*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/all_steps.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/all_steps.dart.weak.outline.expect
index 939b47e..dfe429a 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/all_steps.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/all_steps.dart.weak.outline.expect
@@ -30,7 +30,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class D<X extends self::B<self::D::X*, self::D::Y*>* = self::B<dynamic, dynamic>*, Y extends self::C<self::D::X*, self::D::Y*>* = self::C<dynamic, dynamic>*, Z extends (self::D::Y*) →* self::D::X* = (Null) →* self::B<dynamic, dynamic>*, W extends core::num* = core::num*> extends core::Object {
+class D<X extends self::B<self::D::X*, self::D::Y*>* = self::B<dynamic, dynamic>*, Y extends self::C<self::D::X*, self::D::Y*>* = self::C<dynamic, dynamic>*, Z extends (self::D::Y*) →* self::D::X* = (Null) →* self::B<dynamic, dynamic>*, W extends core::num*> extends core::Object {
   synthetic constructor •() → self::D<self::D::X*, self::D::Y*, self::D::Z*, self::D::W*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/instantiate_to_bound/all_steps.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/all_steps.dart.weak.transformed.expect
index b96266f..336e446 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/all_steps.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/all_steps.dart.weak.transformed.expect
@@ -32,7 +32,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class D<X extends self::B<self::D::X*, self::D::Y*>* = self::B<dynamic, dynamic>*, Y extends self::C<self::D::X*, self::D::Y*>* = self::C<dynamic, dynamic>*, Z extends (self::D::Y*) →* self::D::X* = (Null) →* self::B<dynamic, dynamic>*, W extends core::num* = core::num*> extends core::Object {
+class D<X extends self::B<self::D::X*, self::D::Y*>* = self::B<dynamic, dynamic>*, Y extends self::C<self::D::X*, self::D::Y*>* = self::C<dynamic, dynamic>*, Z extends (self::D::Y*) →* self::D::X* = (Null) →* self::B<dynamic, dynamic>*, W extends core::num*> extends core::Object {
   synthetic constructor •() → self::D<self::D::X*, self::D::Y*, self::D::Z*, self::D::W*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/body_literal_list.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/body_literal_list.dart.weak.expect
index 7089cfc..ff8c02f 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/body_literal_list.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/body_literal_list.dart.weak.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::num* = core::num*> extends core::Object {
+class A<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/body_literal_list.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/body_literal_list.dart.weak.outline.expect
index 67dfa7f..4188002 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/body_literal_list.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/body_literal_list.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::num* = core::num*> extends core::Object {
+class A<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/instantiate_to_bound/body_literal_list.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/body_literal_list.dart.weak.transformed.expect
index c250022..e273fa4 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/body_literal_list.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/body_literal_list.dart.weak.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::num* = core::num*> extends core::Object {
+class A<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/body_literal_map.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/body_literal_map.dart.weak.expect
index 3ab59eb..28c2e96 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/body_literal_map.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/body_literal_map.dart.weak.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::num* = core::num*> extends core::Object {
+class A<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/body_literal_map.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/body_literal_map.dart.weak.outline.expect
index 67dfa7f..4188002 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/body_literal_map.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/body_literal_map.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::num* = core::num*> extends core::Object {
+class A<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/instantiate_to_bound/body_literal_map.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/body_literal_map.dart.weak.transformed.expect
index 3ab59eb..28c2e96 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/body_literal_map.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/body_literal_map.dart.weak.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::num* = core::num*> extends core::Object {
+class A<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/body_typedef_literal_list.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/body_typedef_literal_list.dart.weak.expect
index 0508b6c..19c0496 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/body_typedef_literal_list.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/body_typedef_literal_list.dart.weak.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-typedef A<contravariant T extends core::num* = core::num*> = (T*) →* dynamic;
+typedef A<contravariant T extends core::num*> = (T*) →* dynamic;
 class B extends core::Object {
   synthetic constructor •() → self::B*
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/instantiate_to_bound/body_typedef_literal_list.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/body_typedef_literal_list.dart.weak.outline.expect
index 66230d2..79e9ce6 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/body_typedef_literal_list.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/body_typedef_literal_list.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-typedef A<contravariant T extends core::num* = core::num*> = (T*) →* dynamic;
+typedef A<contravariant T extends core::num*> = (T*) →* dynamic;
 class B extends core::Object {
   synthetic constructor •() → self::B*
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/body_typedef_literal_list.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/body_typedef_literal_list.dart.weak.transformed.expect
index 7f370d6..1c268dc 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/body_typedef_literal_list.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/body_typedef_literal_list.dart.weak.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-typedef A<contravariant T extends core::num* = core::num*> = (T*) →* dynamic;
+typedef A<contravariant T extends core::num*> = (T*) →* dynamic;
 class B extends core::Object {
   synthetic constructor •() → self::B*
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/instantiate_to_bound/body_typedef_literal_map.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/body_typedef_literal_map.dart.weak.expect
index 0b8c7d3..82bfe94 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/body_typedef_literal_map.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/body_typedef_literal_map.dart.weak.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-typedef A<contravariant T extends core::num* = core::num*> = (T*) →* dynamic;
+typedef A<contravariant T extends core::num*> = (T*) →* dynamic;
 class B extends core::Object {
   synthetic constructor •() → self::B*
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/instantiate_to_bound/body_typedef_literal_map.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/body_typedef_literal_map.dart.weak.outline.expect
index 66230d2..79e9ce6 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/body_typedef_literal_map.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/body_typedef_literal_map.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-typedef A<contravariant T extends core::num* = core::num*> = (T*) →* dynamic;
+typedef A<contravariant T extends core::num*> = (T*) →* dynamic;
 class B extends core::Object {
   synthetic constructor •() → self::B*
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/body_typedef_literal_map.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/body_typedef_literal_map.dart.weak.transformed.expect
index 0b8c7d3..82bfe94 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/body_typedef_literal_map.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/body_typedef_literal_map.dart.weak.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-typedef A<contravariant T extends core::num* = core::num*> = (T*) →* dynamic;
+typedef A<contravariant T extends core::num*> = (T*) →* dynamic;
 class B extends core::Object {
   synthetic constructor •() → self::B*
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/instantiate_to_bound/contravariant_dependence.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/contravariant_dependence.dart.weak.expect
index c86f6b2..98dbd20 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/contravariant_dependence.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/contravariant_dependence.dart.weak.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class C<X extends core::num* = core::num*, Y extends (self::C::X*) →* void = (Null) →* void> extends core::Object {
+class C<X extends core::num*, Y extends (self::C::X*) →* void = (Null) →* void> extends core::Object {
   synthetic constructor •() → self::C<self::C::X*, self::C::Y*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/contravariant_dependence.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/contravariant_dependence.dart.weak.outline.expect
index d6d83e0..4906673 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/contravariant_dependence.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/contravariant_dependence.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class C<X extends core::num* = core::num*, Y extends (self::C::X*) →* void = (Null) →* void> extends core::Object {
+class C<X extends core::num*, Y extends (self::C::X*) →* void = (Null) →* void> extends core::Object {
   synthetic constructor •() → self::C<self::C::X*, self::C::Y*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/instantiate_to_bound/contravariant_dependence.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/contravariant_dependence.dart.weak.transformed.expect
index c86f6b2..98dbd20 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/contravariant_dependence.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/contravariant_dependence.dart.weak.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class C<X extends core::num* = core::num*, Y extends (self::C::X*) →* void = (Null) →* void> extends core::Object {
+class C<X extends core::num*, Y extends (self::C::X*) →* void = (Null) →* void> extends core::Object {
   synthetic constructor •() → self::C<self::C::X*, self::C::Y*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/contravariant_dependence_in_literals.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/contravariant_dependence_in_literals.dart.weak.expect
index 52cdb64..a7c105a 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/contravariant_dependence_in_literals.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/contravariant_dependence_in_literals.dart.weak.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class C<X extends core::num* = core::num*, Y extends (self::C::X*) →* void = (Null) →* void> extends core::Object {
+class C<X extends core::num*, Y extends (self::C::X*) →* void = (Null) →* void> extends core::Object {
   synthetic constructor •() → self::C<self::C::X*, self::C::Y*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/contravariant_dependence_in_literals.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/contravariant_dependence_in_literals.dart.weak.outline.expect
index 84e4164..e263f73 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/contravariant_dependence_in_literals.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/contravariant_dependence_in_literals.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class C<X extends core::num* = core::num*, Y extends (self::C::X*) →* void = (Null) →* void> extends core::Object {
+class C<X extends core::num*, Y extends (self::C::X*) →* void = (Null) →* void> extends core::Object {
   synthetic constructor •() → self::C<self::C::X*, self::C::Y*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/instantiate_to_bound/contravariant_dependence_in_literals.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/contravariant_dependence_in_literals.dart.weak.transformed.expect
index a4aa8b0..92a4252 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/contravariant_dependence_in_literals.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/contravariant_dependence_in_literals.dart.weak.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class C<X extends core::num* = core::num*, Y extends (self::C::X*) →* void = (Null) →* void> extends core::Object {
+class C<X extends core::num*, Y extends (self::C::X*) →* void = (Null) →* void> extends core::Object {
   synthetic constructor •() → self::C<self::C::X*, self::C::Y*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/covariant_dependence.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/covariant_dependence.dart.weak.expect
index 0288d9a..5fa1f9e 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/covariant_dependence.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/covariant_dependence.dart.weak.expect
@@ -32,7 +32,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class D<X extends core::num* = core::num*, Y extends self::A<self::D::X*>* = self::A<core::num*>*> extends core::Object {
+class D<X extends core::num*, Y extends self::A<self::D::X*>* = self::A<core::num*>*> extends core::Object {
   synthetic constructor •() → self::D<self::D::X*, self::D::Y*>*
     : super core::Object::•()
     ;
@@ -62,7 +62,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class F<X extends core::num* = core::num*, Y extends () →* self::F::X* = () →* core::num*> extends core::Object {
+class F<X extends core::num*, Y extends () →* self::F::X* = () →* core::num*> extends core::Object {
   synthetic constructor •() → self::F<self::F::X*, self::F::Y*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/covariant_dependence.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/covariant_dependence.dart.weak.outline.expect
index 4d48eae..24c0e8a 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/covariant_dependence.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/covariant_dependence.dart.weak.outline.expect
@@ -30,7 +30,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class D<X extends core::num* = core::num*, Y extends self::A<self::D::X*>* = self::A<core::num*>*> extends core::Object {
+class D<X extends core::num*, Y extends self::A<self::D::X*>* = self::A<core::num*>*> extends core::Object {
   synthetic constructor •() → self::D<self::D::X*, self::D::Y*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
@@ -58,7 +58,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class F<X extends core::num* = core::num*, Y extends () →* self::F::X* = () →* core::num*> extends core::Object {
+class F<X extends core::num*, Y extends () →* self::F::X* = () →* core::num*> extends core::Object {
   synthetic constructor •() → self::F<self::F::X*, self::F::Y*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/instantiate_to_bound/covariant_dependence.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/covariant_dependence.dart.weak.transformed.expect
index 0288d9a..5fa1f9e 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/covariant_dependence.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/covariant_dependence.dart.weak.transformed.expect
@@ -32,7 +32,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class D<X extends core::num* = core::num*, Y extends self::A<self::D::X*>* = self::A<core::num*>*> extends core::Object {
+class D<X extends core::num*, Y extends self::A<self::D::X*>* = self::A<core::num*>*> extends core::Object {
   synthetic constructor •() → self::D<self::D::X*, self::D::Y*>*
     : super core::Object::•()
     ;
@@ -62,7 +62,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class F<X extends core::num* = core::num*, Y extends () →* self::F::X* = () →* core::num*> extends core::Object {
+class F<X extends core::num*, Y extends () →* self::F::X* = () →* core::num*> extends core::Object {
   synthetic constructor •() → self::F<self::F::X*, self::F::Y*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/covariant_dependence_in_literals.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/covariant_dependence_in_literals.dart.weak.expect
index f4627cb..6957306 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/covariant_dependence_in_literals.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/covariant_dependence_in_literals.dart.weak.expect
@@ -32,7 +32,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class D<X extends core::num* = core::num*, Y extends self::A<self::D::X*>* = self::A<core::num*>*> extends core::Object {
+class D<X extends core::num*, Y extends self::A<self::D::X*>* = self::A<core::num*>*> extends core::Object {
   synthetic constructor •() → self::D<self::D::X*, self::D::Y*>*
     : super core::Object::•()
     ;
@@ -62,7 +62,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class F<X extends core::num* = core::num*, Y extends () →* self::F::X* = () →* core::num*> extends core::Object {
+class F<X extends core::num*, Y extends () →* self::F::X* = () →* core::num*> extends core::Object {
   synthetic constructor •() → self::F<self::F::X*, self::F::Y*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/covariant_dependence_in_literals.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/covariant_dependence_in_literals.dart.weak.outline.expect
index fc7f600..8fc64c5 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/covariant_dependence_in_literals.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/covariant_dependence_in_literals.dart.weak.outline.expect
@@ -30,7 +30,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class D<X extends core::num* = core::num*, Y extends self::A<self::D::X*>* = self::A<core::num*>*> extends core::Object {
+class D<X extends core::num*, Y extends self::A<self::D::X*>* = self::A<core::num*>*> extends core::Object {
   synthetic constructor •() → self::D<self::D::X*, self::D::Y*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
@@ -58,7 +58,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class F<X extends core::num* = core::num*, Y extends () →* self::F::X* = () →* core::num*> extends core::Object {
+class F<X extends core::num*, Y extends () →* self::F::X* = () →* core::num*> extends core::Object {
   synthetic constructor •() → self::F<self::F::X*, self::F::Y*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/instantiate_to_bound/covariant_dependence_in_literals.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/covariant_dependence_in_literals.dart.weak.transformed.expect
index 4c4e54a..e6f8f2a 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/covariant_dependence_in_literals.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/covariant_dependence_in_literals.dart.weak.transformed.expect
@@ -32,7 +32,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class D<X extends core::num* = core::num*, Y extends self::A<self::D::X*>* = self::A<core::num*>*> extends core::Object {
+class D<X extends core::num*, Y extends self::A<self::D::X*>* = self::A<core::num*>*> extends core::Object {
   synthetic constructor •() → self::D<self::D::X*, self::D::Y*>*
     : super core::Object::•()
     ;
@@ -62,7 +62,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class F<X extends core::num* = core::num*, Y extends () →* self::F::X* = () →* core::num*> extends core::Object {
+class F<X extends core::num*, Y extends () →* self::F::X* = () →* core::num*> extends core::Object {
   synthetic constructor •() → self::F<self::F::X*, self::F::Y*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/dependence.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/dependence.dart.weak.expect
index 1586c3d..e5f74ce 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/dependence.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/dependence.dart.weak.expect
@@ -32,7 +32,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class D<X extends core::num* = core::num*, Y extends (self::D::X*) →* self::D::X* = (Null) →* core::num*> extends core::Object {
+class D<X extends core::num*, Y extends (self::D::X*) →* self::D::X* = (Null) →* core::num*> extends core::Object {
   synthetic constructor •() → self::D<self::D::X*, self::D::Y*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/dependence.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/dependence.dart.weak.outline.expect
index 7d85a42..6f49703c 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/dependence.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/dependence.dart.weak.outline.expect
@@ -30,7 +30,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class D<X extends core::num* = core::num*, Y extends (self::D::X*) →* self::D::X* = (Null) →* core::num*> extends core::Object {
+class D<X extends core::num*, Y extends (self::D::X*) →* self::D::X* = (Null) →* core::num*> extends core::Object {
   synthetic constructor •() → self::D<self::D::X*, self::D::Y*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/instantiate_to_bound/dependence.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/dependence.dart.weak.transformed.expect
index 1586c3d..e5f74ce 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/dependence.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/dependence.dart.weak.transformed.expect
@@ -32,7 +32,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class D<X extends core::num* = core::num*, Y extends (self::D::X*) →* self::D::X* = (Null) →* core::num*> extends core::Object {
+class D<X extends core::num*, Y extends (self::D::X*) →* self::D::X* = (Null) →* core::num*> extends core::Object {
   synthetic constructor •() → self::D<self::D::X*, self::D::Y*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/dependence_in_literals.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/dependence_in_literals.dart.weak.expect
index edf4bbf..2cf489e 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/dependence_in_literals.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/dependence_in_literals.dart.weak.expect
@@ -32,7 +32,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class D<X extends core::num* = core::num*, Y extends (self::D::X*) →* self::D::X* = (Null) →* core::num*> extends core::Object {
+class D<X extends core::num*, Y extends (self::D::X*) →* self::D::X* = (Null) →* core::num*> extends core::Object {
   synthetic constructor •() → self::D<self::D::X*, self::D::Y*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/dependence_in_literals.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/dependence_in_literals.dart.weak.outline.expect
index e2d5490..b8ba08d 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/dependence_in_literals.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/dependence_in_literals.dart.weak.outline.expect
@@ -30,7 +30,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class D<X extends core::num* = core::num*, Y extends (self::D::X*) →* self::D::X* = (Null) →* core::num*> extends core::Object {
+class D<X extends core::num*, Y extends (self::D::X*) →* self::D::X* = (Null) →* core::num*> extends core::Object {
   synthetic constructor •() → self::D<self::D::X*, self::D::Y*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/instantiate_to_bound/dependence_in_literals.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/dependence_in_literals.dart.weak.transformed.expect
index 71cc20d..a96c10c 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/dependence_in_literals.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/dependence_in_literals.dart.weak.transformed.expect
@@ -32,7 +32,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class D<X extends core::num* = core::num*, Y extends (self::D::X*) →* self::D::X* = (Null) →* core::num*> extends core::Object {
+class D<X extends core::num*, Y extends (self::D::X*) →* self::D::X* = (Null) →* core::num*> extends core::Object {
   synthetic constructor •() → self::D<self::D::X*, self::D::Y*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/inference_constrained_by_bound.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/inference_constrained_by_bound.dart.weak.expect
index 033ea89..5da171e 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/inference_constrained_by_bound.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/inference_constrained_by_bound.dart.weak.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::num* = core::num*> extends core::Object {
+class A<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/inference_constrained_by_bound.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/inference_constrained_by_bound.dart.weak.outline.expect
index ea7a309..408de03 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/inference_constrained_by_bound.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/inference_constrained_by_bound.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::num* = core::num*> extends core::Object {
+class A<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/instantiate_to_bound/inference_constrained_by_bound.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/inference_constrained_by_bound.dart.weak.transformed.expect
index 033ea89..5da171e 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/inference_constrained_by_bound.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/inference_constrained_by_bound.dart.weak.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::num* = core::num*> extends core::Object {
+class A<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/inference_defaults_to_bound.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/inference_defaults_to_bound.dart.weak.expect
index 153ebe1..13d0abf 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/inference_defaults_to_bound.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/inference_defaults_to_bound.dart.weak.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::num* = core::num*> extends core::Object {
+class A<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/inference_defaults_to_bound.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/inference_defaults_to_bound.dart.weak.outline.expect
index ea7a309..408de03 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/inference_defaults_to_bound.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/inference_defaults_to_bound.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::num* = core::num*> extends core::Object {
+class A<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/instantiate_to_bound/inference_defaults_to_bound.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/inference_defaults_to_bound.dart.weak.transformed.expect
index 153ebe1..13d0abf 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/inference_defaults_to_bound.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/inference_defaults_to_bound.dart.weak.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::num* = core::num*> extends core::Object {
+class A<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/inference_gives_input.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/inference_gives_input.dart.weak.expect
index 8dbad85..f971b81 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/inference_gives_input.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/inference_gives_input.dart.weak.expect
@@ -17,7 +17,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class B<T extends core::num* = core::num*, S extends core::List<self::B::T*>* = core::List<core::num*>*> extends self::A<self::B::T*> {
+class B<T extends core::num*, S extends core::List<self::B::T*>* = core::List<core::num*>*> extends self::A<self::B::T*> {
   constructor •([self::B::T* x = #C1]) → self::B<self::B::T*, self::B::S*>*
     : super self::A::•() {}
 }
diff --git a/pkg/front_end/testcases/instantiate_to_bound/inference_gives_input.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/inference_gives_input.dart.weak.outline.expect
index e3cf9c5..933cc07 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/inference_gives_input.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/inference_gives_input.dart.weak.outline.expect
@@ -16,7 +16,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class B<T extends core::num* = core::num*, S extends core::List<self::B::T*>* = core::List<core::num*>*> extends self::A<self::B::T*> {
+class B<T extends core::num*, S extends core::List<self::B::T*>* = core::List<core::num*>*> extends self::A<self::B::T*> {
   constructor •([self::B::T* x]) → self::B<self::B::T*, self::B::S*>*
     ;
 }
diff --git a/pkg/front_end/testcases/instantiate_to_bound/inference_gives_input.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/inference_gives_input.dart.weak.transformed.expect
index 8dbad85..f971b81 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/inference_gives_input.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/inference_gives_input.dart.weak.transformed.expect
@@ -17,7 +17,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class B<T extends core::num* = core::num*, S extends core::List<self::B::T*>* = core::List<core::num*>*> extends self::A<self::B::T*> {
+class B<T extends core::num*, S extends core::List<self::B::T*>* = core::List<core::num*>*> extends self::A<self::B::T*> {
   constructor •([self::B::T* x = #C1]) → self::B<self::B::T*, self::B::S*>*
     : super self::A::•() {}
 }
diff --git a/pkg/front_end/testcases/instantiate_to_bound/instantiated_in_outline.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/instantiated_in_outline.dart.weak.expect
index b24b580..e04675b 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/instantiated_in_outline.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/instantiated_in_outline.dart.weak.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::num* = core::num*> extends core::Object {
+class A<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/instantiated_in_outline.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/instantiated_in_outline.dart.weak.outline.expect
index 29045b9..2886fc8 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/instantiated_in_outline.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/instantiated_in_outline.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::num* = core::num*> extends core::Object {
+class A<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/instantiate_to_bound/instantiated_in_outline.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/instantiated_in_outline.dart.weak.transformed.expect
index b24b580..e04675b 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/instantiated_in_outline.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/instantiated_in_outline.dart.weak.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::num* = core::num*> extends core::Object {
+class A<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/literal_list.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/literal_list.dart.weak.expect
index 33fac9a..f1af679 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/literal_list.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/literal_list.dart.weak.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::num* = core::num*> extends core::Object {
+class A<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/literal_list.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/literal_list.dart.weak.outline.expect
index 2ea894b..ce6b446 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/literal_list.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/literal_list.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::num* = core::num*> extends core::Object {
+class A<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/instantiate_to_bound/literal_list.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/literal_list.dart.weak.transformed.expect
index 1468342..7b0f742 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/literal_list.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/literal_list.dart.weak.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::num* = core::num*> extends core::Object {
+class A<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/literal_map.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/literal_map.dart.weak.expect
index 90e4973..e2fc6ab 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/literal_map.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/literal_map.dart.weak.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::num* = core::num*> extends core::Object {
+class A<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/literal_map.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/literal_map.dart.weak.outline.expect
index f053bc2..64d45b2 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/literal_map.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/literal_map.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::num* = core::num*> extends core::Object {
+class A<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/instantiate_to_bound/literal_map.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/literal_map.dart.weak.transformed.expect
index 90e4973..e2fc6ab 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/literal_map.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/literal_map.dart.weak.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::num* = core::num*> extends core::Object {
+class A<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/multiple_strongly_connected.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/multiple_strongly_connected.dart.weak.expect
index d8cb6c1..1576c98 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/multiple_strongly_connected.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/multiple_strongly_connected.dart.weak.expect
@@ -85,7 +85,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class F<V extends core::num* = core::num*, W extends self::B<self::F::W*, self::F::X*>* = self::B<dynamic, dynamic>*, X extends self::C<self::F::W*, self::F::X*>* = self::C<dynamic, dynamic>*, Y extends self::B<self::F::W*, self::F::X*>* = self::B<self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*>*, Z extends self::C<self::F::Y*, self::F::Z*>* = self::C<self::B<self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*>*, dynamic>*> extends core::Object {
+class F<V extends core::num*, W extends self::B<self::F::W*, self::F::X*>* = self::B<dynamic, dynamic>*, X extends self::C<self::F::W*, self::F::X*>* = self::C<dynamic, dynamic>*, Y extends self::B<self::F::W*, self::F::X*>* = self::B<self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*>*, Z extends self::C<self::F::Y*, self::F::Z*>* = self::C<self::B<self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*>*, dynamic>*> extends core::Object {
   synthetic constructor •() → self::F<self::F::V*, self::F::W*, self::F::X*, self::F::Y*, self::F::Z*>*
     : super core::Object::•()
     ;
@@ -100,7 +100,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class G<V extends core::num* = core::num*, W extends self::B<self::G::V*, self::G::X*>* = self::B<core::num*, dynamic>*, X extends self::C<self::G::W*, self::G::V*>* = self::C<dynamic, core::num*>*, Y extends self::B<self::G::W*, self::G::X*>* = self::B<self::B<core::num*, dynamic>*, self::C<dynamic, core::num*>*>*, Z extends self::C<self::G::Y*, self::G::Z*>* = self::C<self::B<self::B<core::num*, dynamic>*, self::C<dynamic, core::num*>*>*, dynamic>*> extends core::Object {
+class G<V extends core::num*, W extends self::B<self::G::V*, self::G::X*>* = self::B<core::num*, dynamic>*, X extends self::C<self::G::W*, self::G::V*>* = self::C<dynamic, core::num*>*, Y extends self::B<self::G::W*, self::G::X*>* = self::B<self::B<core::num*, dynamic>*, self::C<dynamic, core::num*>*>*, Z extends self::C<self::G::Y*, self::G::Z*>* = self::C<self::B<self::B<core::num*, dynamic>*, self::C<dynamic, core::num*>*>*, dynamic>*> extends core::Object {
   synthetic constructor •() → self::G<self::G::V*, self::G::W*, self::G::X*, self::G::Y*, self::G::Z*>*
     : super core::Object::•()
     ;
@@ -130,7 +130,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class I<T extends invalid-type = invalid-type, U extends self::I::Y* = invalid-type, V extends (self::I::W*) →* dynamic = (Null) →* dynamic, W extends (self::I::X*) →* dynamic = (Null) →* dynamic, X extends (self::I::V*) →* dynamic = (Null) →* dynamic, Y extends self::I::Z* = invalid-type, Z extends self::I::T* = invalid-type> extends core::Object {
+class I<T extends invalid-type, U extends self::I::Y* = invalid-type, V extends (self::I::W*) →* dynamic = (Null) →* dynamic, W extends (self::I::X*) →* dynamic = (Null) →* dynamic, X extends (self::I::V*) →* dynamic = (Null) →* dynamic, Y extends self::I::Z* = invalid-type, Z extends self::I::T* = invalid-type> extends core::Object {
   synthetic constructor •() → self::I<self::I::T*, self::I::U*, self::I::V*, self::I::W*, self::I::X*, self::I::Y*, self::I::Z*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/multiple_strongly_connected.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/multiple_strongly_connected.dart.weak.outline.expect
index df65afc..e29ceb1 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/multiple_strongly_connected.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/multiple_strongly_connected.dart.weak.outline.expect
@@ -80,7 +80,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class F<V extends core::num* = core::num*, W extends self::B<self::F::W*, self::F::X*>* = self::B<dynamic, dynamic>*, X extends self::C<self::F::W*, self::F::X*>* = self::C<dynamic, dynamic>*, Y extends self::B<self::F::W*, self::F::X*>* = self::B<self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*>*, Z extends self::C<self::F::Y*, self::F::Z*>* = self::C<self::B<self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*>*, dynamic>*> extends core::Object {
+class F<V extends core::num*, W extends self::B<self::F::W*, self::F::X*>* = self::B<dynamic, dynamic>*, X extends self::C<self::F::W*, self::F::X*>* = self::C<dynamic, dynamic>*, Y extends self::B<self::F::W*, self::F::X*>* = self::B<self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*>*, Z extends self::C<self::F::Y*, self::F::Z*>* = self::C<self::B<self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*>*, dynamic>*> extends core::Object {
   synthetic constructor •() → self::F<self::F::V*, self::F::W*, self::F::X*, self::F::Y*, self::F::Z*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
@@ -94,7 +94,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class G<V extends core::num* = core::num*, W extends self::B<self::G::V*, self::G::X*>* = self::B<core::num*, dynamic>*, X extends self::C<self::G::W*, self::G::V*>* = self::C<dynamic, core::num*>*, Y extends self::B<self::G::W*, self::G::X*>* = self::B<self::B<core::num*, dynamic>*, self::C<dynamic, core::num*>*>*, Z extends self::C<self::G::Y*, self::G::Z*>* = self::C<self::B<self::B<core::num*, dynamic>*, self::C<dynamic, core::num*>*>*, dynamic>*> extends core::Object {
+class G<V extends core::num*, W extends self::B<self::G::V*, self::G::X*>* = self::B<core::num*, dynamic>*, X extends self::C<self::G::W*, self::G::V*>* = self::C<dynamic, core::num*>*, Y extends self::B<self::G::W*, self::G::X*>* = self::B<self::B<core::num*, dynamic>*, self::C<dynamic, core::num*>*>*, Z extends self::C<self::G::Y*, self::G::Z*>* = self::C<self::B<self::B<core::num*, dynamic>*, self::C<dynamic, core::num*>*>*, dynamic>*> extends core::Object {
   synthetic constructor •() → self::G<self::G::V*, self::G::W*, self::G::X*, self::G::Y*, self::G::Z*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
@@ -122,7 +122,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class I<T extends invalid-type = invalid-type, U extends self::I::Y* = invalid-type, V extends (self::I::W*) →* dynamic = (Null) →* dynamic, W extends (self::I::X*) →* dynamic = (Null) →* dynamic, X extends (self::I::V*) →* dynamic = (Null) →* dynamic, Y extends self::I::Z* = invalid-type, Z extends self::I::T* = invalid-type> extends core::Object {
+class I<T extends invalid-type, U extends self::I::Y* = invalid-type, V extends (self::I::W*) →* dynamic = (Null) →* dynamic, W extends (self::I::X*) →* dynamic = (Null) →* dynamic, X extends (self::I::V*) →* dynamic = (Null) →* dynamic, Y extends self::I::Z* = invalid-type, Z extends self::I::T* = invalid-type> extends core::Object {
   synthetic constructor •() → self::I<self::I::T*, self::I::U*, self::I::V*, self::I::W*, self::I::X*, self::I::Y*, self::I::Z*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/instantiate_to_bound/multiple_strongly_connected.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/multiple_strongly_connected.dart.weak.transformed.expect
index d8cb6c1..1576c98 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/multiple_strongly_connected.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/multiple_strongly_connected.dart.weak.transformed.expect
@@ -85,7 +85,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class F<V extends core::num* = core::num*, W extends self::B<self::F::W*, self::F::X*>* = self::B<dynamic, dynamic>*, X extends self::C<self::F::W*, self::F::X*>* = self::C<dynamic, dynamic>*, Y extends self::B<self::F::W*, self::F::X*>* = self::B<self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*>*, Z extends self::C<self::F::Y*, self::F::Z*>* = self::C<self::B<self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*>*, dynamic>*> extends core::Object {
+class F<V extends core::num*, W extends self::B<self::F::W*, self::F::X*>* = self::B<dynamic, dynamic>*, X extends self::C<self::F::W*, self::F::X*>* = self::C<dynamic, dynamic>*, Y extends self::B<self::F::W*, self::F::X*>* = self::B<self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*>*, Z extends self::C<self::F::Y*, self::F::Z*>* = self::C<self::B<self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*>*, dynamic>*> extends core::Object {
   synthetic constructor •() → self::F<self::F::V*, self::F::W*, self::F::X*, self::F::Y*, self::F::Z*>*
     : super core::Object::•()
     ;
@@ -100,7 +100,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class G<V extends core::num* = core::num*, W extends self::B<self::G::V*, self::G::X*>* = self::B<core::num*, dynamic>*, X extends self::C<self::G::W*, self::G::V*>* = self::C<dynamic, core::num*>*, Y extends self::B<self::G::W*, self::G::X*>* = self::B<self::B<core::num*, dynamic>*, self::C<dynamic, core::num*>*>*, Z extends self::C<self::G::Y*, self::G::Z*>* = self::C<self::B<self::B<core::num*, dynamic>*, self::C<dynamic, core::num*>*>*, dynamic>*> extends core::Object {
+class G<V extends core::num*, W extends self::B<self::G::V*, self::G::X*>* = self::B<core::num*, dynamic>*, X extends self::C<self::G::W*, self::G::V*>* = self::C<dynamic, core::num*>*, Y extends self::B<self::G::W*, self::G::X*>* = self::B<self::B<core::num*, dynamic>*, self::C<dynamic, core::num*>*>*, Z extends self::C<self::G::Y*, self::G::Z*>* = self::C<self::B<self::B<core::num*, dynamic>*, self::C<dynamic, core::num*>*>*, dynamic>*> extends core::Object {
   synthetic constructor •() → self::G<self::G::V*, self::G::W*, self::G::X*, self::G::Y*, self::G::Z*>*
     : super core::Object::•()
     ;
@@ -130,7 +130,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class I<T extends invalid-type = invalid-type, U extends self::I::Y* = invalid-type, V extends (self::I::W*) →* dynamic = (Null) →* dynamic, W extends (self::I::X*) →* dynamic = (Null) →* dynamic, X extends (self::I::V*) →* dynamic = (Null) →* dynamic, Y extends self::I::Z* = invalid-type, Z extends self::I::T* = invalid-type> extends core::Object {
+class I<T extends invalid-type, U extends self::I::Y* = invalid-type, V extends (self::I::W*) →* dynamic = (Null) →* dynamic, W extends (self::I::X*) →* dynamic = (Null) →* dynamic, X extends (self::I::V*) →* dynamic = (Null) →* dynamic, Y extends self::I::Z* = invalid-type, Z extends self::I::T* = invalid-type> extends core::Object {
   synthetic constructor •() → self::I<self::I::T*, self::I::U*, self::I::V*, self::I::W*, self::I::X*, self::I::Y*, self::I::Z*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/non_simple_bound_due_to_non_simple.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/non_simple_bound_due_to_non_simple.dart.weak.expect
index fc99ef9..c15ea34 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/non_simple_bound_due_to_non_simple.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/non_simple_bound_due_to_non_simple.dart.weak.expect
@@ -43,7 +43,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class C<TypeV extends self::B<dynamic>* = self::B<dynamic>*> extends core::Object {
+class C<TypeV extends self::B<dynamic>*> extends core::Object {
   synthetic constructor •() → self::C<self::C::TypeV*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/non_simple_bound_due_to_non_simple.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/non_simple_bound_due_to_non_simple.dart.weak.outline.expect
index ca37d02..b64816e 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/non_simple_bound_due_to_non_simple.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/non_simple_bound_due_to_non_simple.dart.weak.outline.expect
@@ -41,7 +41,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class C<TypeV extends self::B<dynamic>* = self::B<dynamic>*> extends core::Object {
+class C<TypeV extends self::B<dynamic>*> extends core::Object {
   synthetic constructor •() → self::C<self::C::TypeV*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/instantiate_to_bound/non_simple_bound_due_to_non_simple.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/non_simple_bound_due_to_non_simple.dart.weak.transformed.expect
index fc99ef9..c15ea34 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/non_simple_bound_due_to_non_simple.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/non_simple_bound_due_to_non_simple.dart.weak.transformed.expect
@@ -43,7 +43,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class C<TypeV extends self::B<dynamic>* = self::B<dynamic>*> extends core::Object {
+class C<TypeV extends self::B<dynamic>*> extends core::Object {
   synthetic constructor •() → self::C<self::C::TypeV*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/non_simple_class_typedef_cycle.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/non_simple_class_typedef_cycle.dart.weak.expect
index 165ac5e..1adc8bcb 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/non_simple_class_typedef_cycle.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/non_simple_class_typedef_cycle.dart.weak.expect
@@ -17,7 +17,7 @@
 import "dart:core" as core;
 
 typedef Fisk<unrelated TypeY extends core::Object* = dynamic> = () →* void;
-class Hest<TypeX extends () →* void = () →* void> extends core::Object {
+class Hest<TypeX extends () →* void> extends core::Object {
   synthetic constructor •() → self::Hest<self::Hest::TypeX*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/non_simple_class_typedef_cycle.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/non_simple_class_typedef_cycle.dart.weak.outline.expect
index c9e1d02..1828b6d 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/non_simple_class_typedef_cycle.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/non_simple_class_typedef_cycle.dart.weak.outline.expect
@@ -17,7 +17,7 @@
 import "dart:core" as core;
 
 typedef Fisk<unrelated TypeY extends core::Object* = dynamic> = () →* void;
-class Hest<TypeX extends () →* void = () →* void> extends core::Object {
+class Hest<TypeX extends () →* void> extends core::Object {
   synthetic constructor •() → self::Hest<self::Hest::TypeX*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/instantiate_to_bound/non_simple_class_typedef_cycle.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/non_simple_class_typedef_cycle.dart.weak.transformed.expect
index 165ac5e..1adc8bcb 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/non_simple_class_typedef_cycle.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/non_simple_class_typedef_cycle.dart.weak.transformed.expect
@@ -17,7 +17,7 @@
 import "dart:core" as core;
 
 typedef Fisk<unrelated TypeY extends core::Object* = dynamic> = () →* void;
-class Hest<TypeX extends () →* void = () →* void> extends core::Object {
+class Hest<TypeX extends () →* void> extends core::Object {
   synthetic constructor •() → self::Hest<self::Hest::TypeX*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/non_simple_folded_regress.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/non_simple_folded_regress.dart.weak.expect
index 134d69e..f205aa6 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/non_simple_folded_regress.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/non_simple_folded_regress.dart.weak.expect
@@ -17,7 +17,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Fisk<TypeY extends self::Hest<self::Hest<core::Object*>*>* = self::Hest<self::Hest<core::Object*>*>*> extends core::Object {
+class Fisk<TypeY extends self::Hest<self::Hest<core::Object*>*>*> extends core::Object {
   synthetic constructor •() → self::Fisk<self::Fisk::TypeY*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/non_simple_folded_regress.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/non_simple_folded_regress.dart.weak.outline.expect
index 5543106..8159df5 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/non_simple_folded_regress.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/non_simple_folded_regress.dart.weak.outline.expect
@@ -16,7 +16,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Fisk<TypeY extends self::Hest<self::Hest<core::Object*>*>* = self::Hest<self::Hest<core::Object*>*>*> extends core::Object {
+class Fisk<TypeY extends self::Hest<self::Hest<core::Object*>*>*> extends core::Object {
   synthetic constructor •() → self::Fisk<self::Fisk::TypeY*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/instantiate_to_bound/non_simple_folded_regress.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/non_simple_folded_regress.dart.weak.transformed.expect
index 134d69e..f205aa6 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/non_simple_folded_regress.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/non_simple_folded_regress.dart.weak.transformed.expect
@@ -17,7 +17,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Fisk<TypeY extends self::Hest<self::Hest<core::Object*>*>* = self::Hest<self::Hest<core::Object*>*>*> extends core::Object {
+class Fisk<TypeY extends self::Hest<self::Hest<core::Object*>*>*> extends core::Object {
   synthetic constructor •() → self::Fisk<self::Fisk::TypeY*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/non_simple_many_libs_same_name_cycle.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/non_simple_many_libs_same_name_cycle.dart.weak.expect
index 132a9fd..0124e15 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/non_simple_many_libs_same_name_cycle.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/non_simple_many_libs_same_name_cycle.dart.weak.expect
@@ -42,7 +42,7 @@
 
 import "org-dartlang-testcase:///non_simple_many_libs_same_name_cycle.dart" as lib;
 
-class Hest<TypeY extends self::Hest<dynamic>* = self::Hest<dynamic>*> extends core::Object {
+class Hest<TypeY extends self::Hest<dynamic>*> extends core::Object {
   synthetic constructor •() → self2::Hest<self2::Hest::TypeY*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/non_simple_many_libs_same_name_cycle.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/non_simple_many_libs_same_name_cycle.dart.weak.outline.expect
index 573dcb4..e783ebd 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/non_simple_many_libs_same_name_cycle.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/non_simple_many_libs_same_name_cycle.dart.weak.outline.expect
@@ -42,7 +42,7 @@
 
 import "org-dartlang-testcase:///non_simple_many_libs_same_name_cycle.dart" as lib;
 
-class Hest<TypeY extends self::Hest<dynamic>* = self::Hest<dynamic>*> extends core::Object {
+class Hest<TypeY extends self::Hest<dynamic>*> extends core::Object {
   synthetic constructor •() → self2::Hest<self2::Hest::TypeY*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/instantiate_to_bound/non_simple_many_libs_same_name_cycle.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/non_simple_many_libs_same_name_cycle.dart.weak.transformed.expect
index 132a9fd..0124e15 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/non_simple_many_libs_same_name_cycle.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/non_simple_many_libs_same_name_cycle.dart.weak.transformed.expect
@@ -42,7 +42,7 @@
 
 import "org-dartlang-testcase:///non_simple_many_libs_same_name_cycle.dart" as lib;
 
-class Hest<TypeY extends self::Hest<dynamic>* = self::Hest<dynamic>*> extends core::Object {
+class Hest<TypeY extends self::Hest<dynamic>*> extends core::Object {
   synthetic constructor •() → self2::Hest<self2::Hest::TypeY*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/non_simple_suppress_consequence.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/non_simple_suppress_consequence.dart.weak.expect
index 570251f..34ba795 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/non_simple_suppress_consequence.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/non_simple_suppress_consequence.dart.weak.expect
@@ -43,7 +43,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Naebdyr<TypeZ extends self::Fisk<dynamic>* = self::Fisk<dynamic>*> extends core::Object {
+class Naebdyr<TypeZ extends self::Fisk<dynamic>*> extends core::Object {
   synthetic constructor •() → self::Naebdyr<self::Naebdyr::TypeZ*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/non_simple_suppress_consequence.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/non_simple_suppress_consequence.dart.weak.outline.expect
index e894bff..4c03b0d 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/non_simple_suppress_consequence.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/non_simple_suppress_consequence.dart.weak.outline.expect
@@ -41,7 +41,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Naebdyr<TypeZ extends self::Fisk<dynamic>* = self::Fisk<dynamic>*> extends core::Object {
+class Naebdyr<TypeZ extends self::Fisk<dynamic>*> extends core::Object {
   synthetic constructor •() → self::Naebdyr<self::Naebdyr::TypeZ*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/instantiate_to_bound/non_simple_suppress_consequence.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/non_simple_suppress_consequence.dart.weak.transformed.expect
index 570251f..34ba795 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/non_simple_suppress_consequence.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/non_simple_suppress_consequence.dart.weak.transformed.expect
@@ -43,7 +43,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class Naebdyr<TypeZ extends self::Fisk<dynamic>* = self::Fisk<dynamic>*> extends core::Object {
+class Naebdyr<TypeZ extends self::Fisk<dynamic>*> extends core::Object {
   synthetic constructor •() → self::Naebdyr<self::Naebdyr::TypeZ*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/raw_in_bound.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/raw_in_bound.dart.weak.expect
index 28149f2..97505bc 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/raw_in_bound.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/raw_in_bound.dart.weak.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::num* = core::num*> extends core::Object {
+class A<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     : super core::Object::•()
     ;
@@ -17,7 +17,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class B<T extends self::A<core::num*>* = self::A<core::num*>*> extends core::Object {
+class B<T extends self::A<core::num*>*> extends core::Object {
   synthetic constructor •() → self::B<self::B::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/raw_in_bound.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/raw_in_bound.dart.weak.outline.expect
index 3de42af..86a3170 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/raw_in_bound.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/raw_in_bound.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::num* = core::num*> extends core::Object {
+class A<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
@@ -16,7 +16,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class B<T extends self::A<core::num*>* = self::A<core::num*>*> extends core::Object {
+class B<T extends self::A<core::num*>*> extends core::Object {
   synthetic constructor •() → self::B<self::B::T*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/instantiate_to_bound/raw_in_bound.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/raw_in_bound.dart.weak.transformed.expect
index 28149f2..97505bc 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/raw_in_bound.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/raw_in_bound.dart.weak.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::num* = core::num*> extends core::Object {
+class A<T extends core::num*> extends core::Object {
   synthetic constructor •() → self::A<self::A::T*>*
     : super core::Object::•()
     ;
@@ -17,7 +17,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class B<T extends self::A<core::num*>* = self::A<core::num*>*> extends core::Object {
+class B<T extends self::A<core::num*>*> extends core::Object {
   synthetic constructor •() → self::B<self::B::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/super_bounded_in_bound.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/super_bounded_in_bound.dart.weak.expect
index 7253b00..5ec3988 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/super_bounded_in_bound.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/super_bounded_in_bound.dart.weak.expect
@@ -17,7 +17,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class B<Y extends self::A<dynamic>* = self::A<dynamic>*> extends core::Object {
+class B<Y extends self::A<dynamic>*> extends core::Object {
   synthetic constructor •() → self::B<self::B::Y*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/super_bounded_in_bound.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/super_bounded_in_bound.dart.weak.outline.expect
index 526b4dc..c896444 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/super_bounded_in_bound.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/super_bounded_in_bound.dart.weak.outline.expect
@@ -16,7 +16,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class B<Y extends self::A<dynamic>* = self::A<dynamic>*> extends core::Object {
+class B<Y extends self::A<dynamic>*> extends core::Object {
   synthetic constructor •() → self::B<self::B::Y*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/instantiate_to_bound/super_bounded_in_bound.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/super_bounded_in_bound.dart.weak.transformed.expect
index 7253b00..5ec3988 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/super_bounded_in_bound.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/super_bounded_in_bound.dart.weak.transformed.expect
@@ -17,7 +17,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class B<Y extends self::A<dynamic>* = self::A<dynamic>*> extends core::Object {
+class B<Y extends self::A<dynamic>*> extends core::Object {
   synthetic constructor •() → self::B<self::B::Y*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/supertypes.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/supertypes.dart.weak.expect
index 05e4575..fbb18cb 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/supertypes.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/supertypes.dart.weak.expect
@@ -20,7 +20,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class X<T extends self::B* = self::B*> extends core::Object {
+class X<T extends self::B*> extends core::Object {
   synthetic constructor •() → self::X<self::X::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/supertypes.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/supertypes.dart.weak.outline.expect
index 9d44acf..43c0107 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/supertypes.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/supertypes.dart.weak.outline.expect
@@ -18,7 +18,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class X<T extends self::B* = self::B*> extends core::Object {
+class X<T extends self::B*> extends core::Object {
   synthetic constructor •() → self::X<self::X::T*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/instantiate_to_bound/supertypes.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/supertypes.dart.weak.transformed.expect
index 05e4575..fbb18cb 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/supertypes.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/supertypes.dart.weak.transformed.expect
@@ -20,7 +20,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-class X<T extends self::B* = self::B*> extends core::Object {
+class X<T extends self::B*> extends core::Object {
   synthetic constructor •() → self::X<self::X::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/typedef_instantiated_in_outline.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/typedef_instantiated_in_outline.dart.weak.expect
index 650f258..1e4c90a 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/typedef_instantiated_in_outline.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/typedef_instantiated_in_outline.dart.weak.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-typedef A<contravariant T extends core::num* = core::num*> = (T*) →* dynamic;
+typedef A<contravariant T extends core::num*> = (T*) →* dynamic;
 class B extends core::Object {
   synthetic constructor •() → self::B*
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/instantiate_to_bound/typedef_instantiated_in_outline.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/typedef_instantiated_in_outline.dart.weak.outline.expect
index c798857..bd8b1e2 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/typedef_instantiated_in_outline.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/typedef_instantiated_in_outline.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-typedef A<contravariant T extends core::num* = core::num*> = (T*) →* dynamic;
+typedef A<contravariant T extends core::num*> = (T*) →* dynamic;
 class B extends core::Object {
   synthetic constructor •() → self::B*
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/typedef_instantiated_in_outline.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/typedef_instantiated_in_outline.dart.weak.transformed.expect
index 650f258..1e4c90a 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/typedef_instantiated_in_outline.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/typedef_instantiated_in_outline.dart.weak.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-typedef A<contravariant T extends core::num* = core::num*> = (T*) →* dynamic;
+typedef A<contravariant T extends core::num*> = (T*) →* dynamic;
 class B extends core::Object {
   synthetic constructor •() → self::B*
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/instantiate_to_bound/typedef_literal_list.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/typedef_literal_list.dart.weak.expect
index e5555e7..954f38c 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/typedef_literal_list.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/typedef_literal_list.dart.weak.expect
@@ -2,6 +2,6 @@
 import self as self;
 import "dart:core" as core;
 
-typedef A<contravariant T extends core::num* = core::num*> = (T*) →* dynamic;
+typedef A<contravariant T extends core::num*> = (T*) →* dynamic;
 static field core::List<(core::num*) →* dynamic>* a = <(core::num*) →* dynamic>[];
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/instantiate_to_bound/typedef_literal_list.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/typedef_literal_list.dart.weak.outline.expect
index e6917ea..88f9288 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/typedef_literal_list.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/typedef_literal_list.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-typedef A<contravariant T extends core::num* = core::num*> = (T*) →* dynamic;
+typedef A<contravariant T extends core::num*> = (T*) →* dynamic;
 static field core::List<(core::num*) →* dynamic>* a;
 static method main() → dynamic
   ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/typedef_literal_list.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/typedef_literal_list.dart.weak.transformed.expect
index 94f6c04..bf9f10e 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/typedef_literal_list.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/typedef_literal_list.dart.weak.transformed.expect
@@ -2,6 +2,6 @@
 import self as self;
 import "dart:core" as core;
 
-typedef A<contravariant T extends core::num* = core::num*> = (T*) →* dynamic;
+typedef A<contravariant T extends core::num*> = (T*) →* dynamic;
 static field core::List<(core::num*) →* dynamic>* a = core::_GrowableList::•<(core::num*) →* dynamic>(0);
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/instantiate_to_bound/typedef_literal_map.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/typedef_literal_map.dart.weak.expect
index 5412826..0914a2c 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/typedef_literal_map.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/typedef_literal_map.dart.weak.expect
@@ -2,6 +2,6 @@
 import self as self;
 import "dart:core" as core;
 
-typedef A<contravariant T extends core::num* = core::num*> = (T*) →* dynamic;
+typedef A<contravariant T extends core::num*> = (T*) →* dynamic;
 static field core::Map<(core::num*) →* dynamic, (core::num*) →* dynamic>* a = <(core::num*) →* dynamic, (core::num*) →* dynamic>{};
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/instantiate_to_bound/typedef_literal_map.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/typedef_literal_map.dart.weak.outline.expect
index 90306c1..9f56108 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/typedef_literal_map.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/typedef_literal_map.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-typedef A<contravariant T extends core::num* = core::num*> = (T*) →* dynamic;
+typedef A<contravariant T extends core::num*> = (T*) →* dynamic;
 static field core::Map<(core::num*) →* dynamic, (core::num*) →* dynamic>* a;
 static method main() → dynamic
   ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/typedef_literal_map.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/typedef_literal_map.dart.weak.transformed.expect
index 5412826..0914a2c 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/typedef_literal_map.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/typedef_literal_map.dart.weak.transformed.expect
@@ -2,6 +2,6 @@
 import self as self;
 import "dart:core" as core;
 
-typedef A<contravariant T extends core::num* = core::num*> = (T*) →* dynamic;
+typedef A<contravariant T extends core::num*> = (T*) →* dynamic;
 static field core::Map<(core::num*) →* dynamic, (core::num*) →* dynamic>* a = <(core::num*) →* dynamic, (core::num*) →* dynamic>{};
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/instantiate_to_bound/typedef_raw_in_bound.dart.weak.expect b/pkg/front_end/testcases/instantiate_to_bound/typedef_raw_in_bound.dart.weak.expect
index f68319b..f32d1b22 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/typedef_raw_in_bound.dart.weak.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/typedef_raw_in_bound.dart.weak.expect
@@ -2,8 +2,8 @@
 import self as self;
 import "dart:core" as core;
 
-typedef A<contravariant T extends core::num* = core::num*> = (T*) →* dynamic;
-class B<T extends (core::num*) →* dynamic = (core::num*) →* dynamic> extends core::Object {
+typedef A<contravariant T extends core::num*> = (T*) →* dynamic;
+class B<T extends (core::num*) →* dynamic> extends core::Object {
   synthetic constructor •() → self::B<self::B::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/instantiate_to_bound/typedef_raw_in_bound.dart.weak.outline.expect b/pkg/front_end/testcases/instantiate_to_bound/typedef_raw_in_bound.dart.weak.outline.expect
index c7b5f33..8f890d3 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/typedef_raw_in_bound.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/typedef_raw_in_bound.dart.weak.outline.expect
@@ -2,8 +2,8 @@
 import self as self;
 import "dart:core" as core;
 
-typedef A<contravariant T extends core::num* = core::num*> = (T*) →* dynamic;
-class B<T extends (core::num*) →* dynamic = (core::num*) →* dynamic> extends core::Object {
+typedef A<contravariant T extends core::num*> = (T*) →* dynamic;
+class B<T extends (core::num*) →* dynamic> extends core::Object {
   synthetic constructor •() → self::B<self::B::T*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/instantiate_to_bound/typedef_raw_in_bound.dart.weak.transformed.expect b/pkg/front_end/testcases/instantiate_to_bound/typedef_raw_in_bound.dart.weak.transformed.expect
index f68319b..f32d1b22 100644
--- a/pkg/front_end/testcases/instantiate_to_bound/typedef_raw_in_bound.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/instantiate_to_bound/typedef_raw_in_bound.dart.weak.transformed.expect
@@ -2,8 +2,8 @@
 import self as self;
 import "dart:core" as core;
 
-typedef A<contravariant T extends core::num* = core::num*> = (T*) →* dynamic;
-class B<T extends (core::num*) →* dynamic = (core::num*) →* dynamic> extends core::Object {
+typedef A<contravariant T extends core::num*> = (T*) →* dynamic;
+class B<T extends (core::num*) →* dynamic> extends core::Object {
   synthetic constructor •() → self::B<self::B::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/late_lowering/non_nullable_from_opt_out.dart.strong.expect b/pkg/front_end/testcases/late_lowering/non_nullable_from_opt_out.dart.strong.expect
index 184faaf..9e954be 100644
--- a/pkg/front_end/testcases/late_lowering/non_nullable_from_opt_out.dart.strong.expect
+++ b/pkg/front_end/testcases/late_lowering/non_nullable_from_opt_out.dart.strong.expect
@@ -42,7 +42,7 @@
 import "dart:core" as core;
 import "dart:_internal" as _in;
 
-class Class<T extends core::Object = core::Object> extends core::Object {
+class Class<T extends core::Object> extends core::Object {
   field core::int? _#Class#instanceField = null;
   field dynamic _#Class#finalInstanceField = null;
   field core::bool _#Class#finalInstanceField#isSet = false;
@@ -108,7 +108,7 @@
     non::_#finalTopLevelField#isSet = true;
     non::_#finalTopLevelField = #t13;
   }
-static method method<T extends core::Object = core::Object>(core::bool b, core::int i, non::method::T t) → dynamic {
+static method method<T extends core::Object>(core::bool b, core::int i, non::method::T t) → dynamic {
   lowered core::int? #local;
   function #local#get() → core::int
     return let final core::int? #t14 = #local in #t14.==(null) ?{core::int} throw new _in::LateError::localNI("local") : #t14{core::int};
diff --git a/pkg/front_end/testcases/late_lowering/non_nullable_from_opt_out.dart.strong.transformed.expect b/pkg/front_end/testcases/late_lowering/non_nullable_from_opt_out.dart.strong.transformed.expect
index 184faaf..9e954be 100644
--- a/pkg/front_end/testcases/late_lowering/non_nullable_from_opt_out.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/late_lowering/non_nullable_from_opt_out.dart.strong.transformed.expect
@@ -42,7 +42,7 @@
 import "dart:core" as core;
 import "dart:_internal" as _in;
 
-class Class<T extends core::Object = core::Object> extends core::Object {
+class Class<T extends core::Object> extends core::Object {
   field core::int? _#Class#instanceField = null;
   field dynamic _#Class#finalInstanceField = null;
   field core::bool _#Class#finalInstanceField#isSet = false;
@@ -108,7 +108,7 @@
     non::_#finalTopLevelField#isSet = true;
     non::_#finalTopLevelField = #t13;
   }
-static method method<T extends core::Object = core::Object>(core::bool b, core::int i, non::method::T t) → dynamic {
+static method method<T extends core::Object>(core::bool b, core::int i, non::method::T t) → dynamic {
   lowered core::int? #local;
   function #local#get() → core::int
     return let final core::int? #t14 = #local in #t14.==(null) ?{core::int} throw new _in::LateError::localNI("local") : #t14{core::int};
diff --git a/pkg/front_end/testcases/late_lowering/non_nullable_from_opt_out.dart.weak.expect b/pkg/front_end/testcases/late_lowering/non_nullable_from_opt_out.dart.weak.expect
index 7555788..f6a85c7 100644
--- a/pkg/front_end/testcases/late_lowering/non_nullable_from_opt_out.dart.weak.expect
+++ b/pkg/front_end/testcases/late_lowering/non_nullable_from_opt_out.dart.weak.expect
@@ -35,7 +35,7 @@
 import "dart:core" as core;
 import "dart:_internal" as _in;
 
-class Class<T extends core::Object = core::Object> extends core::Object {
+class Class<T extends core::Object> extends core::Object {
   field core::int? _#Class#instanceField = null;
   field core::bool _#Class#instanceField#isSet = false;
   field dynamic _#Class#finalInstanceField = null;
@@ -116,7 +116,7 @@
     non::_#finalTopLevelField#isSet = true;
     non::_#finalTopLevelField = #t13;
   }
-static method method<T extends core::Object = core::Object>(core::bool b, core::int i, non::method::T t) → dynamic {
+static method method<T extends core::Object>(core::bool b, core::int i, non::method::T t) → dynamic {
   lowered core::int? #local;
   lowered core::bool #local#isSet = false;
   function #local#get() → core::int
diff --git a/pkg/front_end/testcases/late_lowering/non_nullable_from_opt_out.dart.weak.outline.expect b/pkg/front_end/testcases/late_lowering/non_nullable_from_opt_out.dart.weak.outline.expect
index c050791..1c5d975 100644
--- a/pkg/front_end/testcases/late_lowering/non_nullable_from_opt_out.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/late_lowering/non_nullable_from_opt_out.dart.weak.outline.expect
@@ -10,7 +10,7 @@
 import self as self2;
 import "dart:core" as core;
 
-class Class<T extends core::Object = core::Object> extends core::Object {
+class Class<T extends core::Object> extends core::Object {
   field core::int? _#Class#instanceField;
   field core::bool _#Class#instanceField#isSet;
   field dynamic _#Class#finalInstanceField;
@@ -46,7 +46,7 @@
 static set topLevelField(core::int #t7) → void;
 static get finalTopLevelField() → dynamic;
 static set finalTopLevelField(dynamic #t8) → void;
-static method method<T extends core::Object = core::Object>(core::bool b, core::int i, self2::method::T t) → dynamic
+static method method<T extends core::Object>(core::bool b, core::int i, self2::method::T t) → dynamic
   ;
 static method expect(dynamic expected, dynamic actual) → dynamic
   ;
diff --git a/pkg/front_end/testcases/late_lowering/non_nullable_from_opt_out.dart.weak.transformed.expect b/pkg/front_end/testcases/late_lowering/non_nullable_from_opt_out.dart.weak.transformed.expect
index 7555788..f6a85c7 100644
--- a/pkg/front_end/testcases/late_lowering/non_nullable_from_opt_out.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/late_lowering/non_nullable_from_opt_out.dart.weak.transformed.expect
@@ -35,7 +35,7 @@
 import "dart:core" as core;
 import "dart:_internal" as _in;
 
-class Class<T extends core::Object = core::Object> extends core::Object {
+class Class<T extends core::Object> extends core::Object {
   field core::int? _#Class#instanceField = null;
   field core::bool _#Class#instanceField#isSet = false;
   field dynamic _#Class#finalInstanceField = null;
@@ -116,7 +116,7 @@
     non::_#finalTopLevelField#isSet = true;
     non::_#finalTopLevelField = #t13;
   }
-static method method<T extends core::Object = core::Object>(core::bool b, core::int i, non::method::T t) → dynamic {
+static method method<T extends core::Object>(core::bool b, core::int i, non::method::T t) → dynamic {
   lowered core::int? #local;
   lowered core::bool #local#isSet = false;
   function #local#get() → core::int
diff --git a/pkg/front_end/testcases/nnbd/assignability.dart.strong.expect b/pkg/front_end/testcases/nnbd/assignability.dart.strong.expect
index 5048e4b..19d474e 100644
--- a/pkg/front_end/testcases/nnbd/assignability.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/assignability.dart.strong.expect
@@ -981,7 +981,7 @@
     ;
   method call() → void {}
 }
-static method ok<XnonNull extends core::Object = core::Object, YnonNull extends self::ok::XnonNull = core::Object, XpotentiallyNull extends core::Object? = core::Object?, YpotentiallyNull extends self::ok::XpotentiallyNull% = core::Object?>(dynamic dynamicArg, core::Object objectArg, core::num numArg, core::int intArg, core::double doubleArg, core::Function functionArg, () → void toVoidArg, self::Tearoffable tearoffableArg, self::ok::XnonNull xNonNullArg, self::ok::XpotentiallyNull% xPotentiallyNullArg, self::ok::YnonNull yNonNullArg, self::ok::YpotentiallyNull% yPotentiallyNullArg) → dynamic {
+static method ok<XnonNull extends core::Object, YnonNull extends self::ok::XnonNull = core::Object, XpotentiallyNull extends core::Object?, YpotentiallyNull extends self::ok::XpotentiallyNull% = core::Object?>(dynamic dynamicArg, core::Object objectArg, core::num numArg, core::int intArg, core::double doubleArg, core::Function functionArg, () → void toVoidArg, self::Tearoffable tearoffableArg, self::ok::XnonNull xNonNullArg, self::ok::XpotentiallyNull% xPotentiallyNullArg, self::ok::YnonNull yNonNullArg, self::ok::YpotentiallyNull% yPotentiallyNullArg) → dynamic {
   dynamic dynamicVar = dynamicArg;
   dynamicVar = objectArg;
   dynamicVar = numArg;
@@ -1031,7 +1031,7 @@
   self::ok::YpotentiallyNull% yPotentiallyNullVar = dynamicArg as{TypeError,ForDynamic,ForNonNullableByDefault} self::ok::YpotentiallyNull%;
   yPotentiallyNullVar = yPotentiallyNullArg;
 }
-static method error<XnonNull extends core::Object = core::Object, YnonNull extends self::error::XnonNull = core::Object, XpotentiallyNull extends core::Object? = core::Object?, YpotentiallyNull extends self::error::XpotentiallyNull% = core::Object?>(core::Object objectArg, core::Object? objectNullableArg, core::num numArg, core::num? numNullableArg, core::int intArg, core::int? intNullableArg, core::double doubleArg, core::double? doubleNullableArg, core::Function functionArg, core::Function? functionNullableArg, () → void toVoidArg, () →? void toVoidNullableArg, self::Tearoffable tearoffableArg, self::Tearoffable? tearoffableNullableArg, self::error::XnonNull xNonNullArg, self::error::XnonNull? xNonNullNullableArg, self::error::XpotentiallyNull% xPotentiallyNullArg, self::error::XpotentiallyNull? xPotentiallyNullNullableArg, self::error::YnonNull yNonNullArg, self::error::YnonNull? yNonNullNullableArg, self::error::YpotentiallyNull% yPotentiallyNullArg, self::error::YpotentiallyNull? yPotentiallyNullNullableArg) → dynamic {
+static method error<XnonNull extends core::Object, YnonNull extends self::error::XnonNull = core::Object, XpotentiallyNull extends core::Object?, YpotentiallyNull extends self::error::XpotentiallyNull% = core::Object?>(core::Object objectArg, core::Object? objectNullableArg, core::num numArg, core::num? numNullableArg, core::int intArg, core::int? intNullableArg, core::double doubleArg, core::double? doubleNullableArg, core::Function functionArg, core::Function? functionNullableArg, () → void toVoidArg, () →? void toVoidNullableArg, self::Tearoffable tearoffableArg, self::Tearoffable? tearoffableNullableArg, self::error::XnonNull xNonNullArg, self::error::XnonNull? xNonNullNullableArg, self::error::XpotentiallyNull% xPotentiallyNullArg, self::error::XpotentiallyNull? xPotentiallyNullNullableArg, self::error::YnonNull yNonNullArg, self::error::YnonNull? yNonNullNullableArg, self::error::YpotentiallyNull% yPotentiallyNullArg, self::error::YpotentiallyNull? yPotentiallyNullNullableArg) → dynamic {
   core::Object objectVar = let final Never #t3 = invalid-expression "pkg/front_end/testcases/nnbd/assignability.dart:114:22: Error: A value of type 'Object?' can't be assigned to a variable of type 'Object' because 'Object?' is nullable and 'Object' isn't.
  - 'Object' is from 'dart:core'.
   Object objectVar = objectNullableArg;
diff --git a/pkg/front_end/testcases/nnbd/assignability.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/assignability.dart.strong.transformed.expect
index 1511c7e..0c62a44 100644
--- a/pkg/front_end/testcases/nnbd/assignability.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/assignability.dart.strong.transformed.expect
@@ -981,7 +981,7 @@
     ;
   method call() → void {}
 }
-static method ok<XnonNull extends core::Object = core::Object, YnonNull extends self::ok::XnonNull = core::Object, XpotentiallyNull extends core::Object? = core::Object?, YpotentiallyNull extends self::ok::XpotentiallyNull% = core::Object?>(dynamic dynamicArg, core::Object objectArg, core::num numArg, core::int intArg, core::double doubleArg, core::Function functionArg, () → void toVoidArg, self::Tearoffable tearoffableArg, self::ok::XnonNull xNonNullArg, self::ok::XpotentiallyNull% xPotentiallyNullArg, self::ok::YnonNull yNonNullArg, self::ok::YpotentiallyNull% yPotentiallyNullArg) → dynamic {
+static method ok<XnonNull extends core::Object, YnonNull extends self::ok::XnonNull = core::Object, XpotentiallyNull extends core::Object?, YpotentiallyNull extends self::ok::XpotentiallyNull% = core::Object?>(dynamic dynamicArg, core::Object objectArg, core::num numArg, core::int intArg, core::double doubleArg, core::Function functionArg, () → void toVoidArg, self::Tearoffable tearoffableArg, self::ok::XnonNull xNonNullArg, self::ok::XpotentiallyNull% xPotentiallyNullArg, self::ok::YnonNull yNonNullArg, self::ok::YpotentiallyNull% yPotentiallyNullArg) → dynamic {
   dynamic dynamicVar = dynamicArg;
   dynamicVar = objectArg;
   dynamicVar = numArg;
@@ -1031,7 +1031,7 @@
   self::ok::YpotentiallyNull% yPotentiallyNullVar = dynamicArg as{TypeError,ForDynamic,ForNonNullableByDefault} self::ok::YpotentiallyNull%;
   yPotentiallyNullVar = yPotentiallyNullArg;
 }
-static method error<XnonNull extends core::Object = core::Object, YnonNull extends self::error::XnonNull = core::Object, XpotentiallyNull extends core::Object? = core::Object?, YpotentiallyNull extends self::error::XpotentiallyNull% = core::Object?>(core::Object objectArg, core::Object? objectNullableArg, core::num numArg, core::num? numNullableArg, core::int intArg, core::int? intNullableArg, core::double doubleArg, core::double? doubleNullableArg, core::Function functionArg, core::Function? functionNullableArg, () → void toVoidArg, () →? void toVoidNullableArg, self::Tearoffable tearoffableArg, self::Tearoffable? tearoffableNullableArg, self::error::XnonNull xNonNullArg, self::error::XnonNull? xNonNullNullableArg, self::error::XpotentiallyNull% xPotentiallyNullArg, self::error::XpotentiallyNull? xPotentiallyNullNullableArg, self::error::YnonNull yNonNullArg, self::error::YnonNull? yNonNullNullableArg, self::error::YpotentiallyNull% yPotentiallyNullArg, self::error::YpotentiallyNull? yPotentiallyNullNullableArg) → dynamic {
+static method error<XnonNull extends core::Object, YnonNull extends self::error::XnonNull = core::Object, XpotentiallyNull extends core::Object?, YpotentiallyNull extends self::error::XpotentiallyNull% = core::Object?>(core::Object objectArg, core::Object? objectNullableArg, core::num numArg, core::num? numNullableArg, core::int intArg, core::int? intNullableArg, core::double doubleArg, core::double? doubleNullableArg, core::Function functionArg, core::Function? functionNullableArg, () → void toVoidArg, () →? void toVoidNullableArg, self::Tearoffable tearoffableArg, self::Tearoffable? tearoffableNullableArg, self::error::XnonNull xNonNullArg, self::error::XnonNull? xNonNullNullableArg, self::error::XpotentiallyNull% xPotentiallyNullArg, self::error::XpotentiallyNull? xPotentiallyNullNullableArg, self::error::YnonNull yNonNullArg, self::error::YnonNull? yNonNullNullableArg, self::error::YpotentiallyNull% yPotentiallyNullArg, self::error::YpotentiallyNull? yPotentiallyNullNullableArg) → dynamic {
   core::Object objectVar = let final Never #t4 = invalid-expression "pkg/front_end/testcases/nnbd/assignability.dart:114:22: Error: A value of type 'Object?' can't be assigned to a variable of type 'Object' because 'Object?' is nullable and 'Object' isn't.
  - 'Object' is from 'dart:core'.
   Object objectVar = objectNullableArg;
diff --git a/pkg/front_end/testcases/nnbd/assignability.dart.weak.expect b/pkg/front_end/testcases/nnbd/assignability.dart.weak.expect
index 5048e4b..19d474e 100644
--- a/pkg/front_end/testcases/nnbd/assignability.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/assignability.dart.weak.expect
@@ -981,7 +981,7 @@
     ;
   method call() → void {}
 }
-static method ok<XnonNull extends core::Object = core::Object, YnonNull extends self::ok::XnonNull = core::Object, XpotentiallyNull extends core::Object? = core::Object?, YpotentiallyNull extends self::ok::XpotentiallyNull% = core::Object?>(dynamic dynamicArg, core::Object objectArg, core::num numArg, core::int intArg, core::double doubleArg, core::Function functionArg, () → void toVoidArg, self::Tearoffable tearoffableArg, self::ok::XnonNull xNonNullArg, self::ok::XpotentiallyNull% xPotentiallyNullArg, self::ok::YnonNull yNonNullArg, self::ok::YpotentiallyNull% yPotentiallyNullArg) → dynamic {
+static method ok<XnonNull extends core::Object, YnonNull extends self::ok::XnonNull = core::Object, XpotentiallyNull extends core::Object?, YpotentiallyNull extends self::ok::XpotentiallyNull% = core::Object?>(dynamic dynamicArg, core::Object objectArg, core::num numArg, core::int intArg, core::double doubleArg, core::Function functionArg, () → void toVoidArg, self::Tearoffable tearoffableArg, self::ok::XnonNull xNonNullArg, self::ok::XpotentiallyNull% xPotentiallyNullArg, self::ok::YnonNull yNonNullArg, self::ok::YpotentiallyNull% yPotentiallyNullArg) → dynamic {
   dynamic dynamicVar = dynamicArg;
   dynamicVar = objectArg;
   dynamicVar = numArg;
@@ -1031,7 +1031,7 @@
   self::ok::YpotentiallyNull% yPotentiallyNullVar = dynamicArg as{TypeError,ForDynamic,ForNonNullableByDefault} self::ok::YpotentiallyNull%;
   yPotentiallyNullVar = yPotentiallyNullArg;
 }
-static method error<XnonNull extends core::Object = core::Object, YnonNull extends self::error::XnonNull = core::Object, XpotentiallyNull extends core::Object? = core::Object?, YpotentiallyNull extends self::error::XpotentiallyNull% = core::Object?>(core::Object objectArg, core::Object? objectNullableArg, core::num numArg, core::num? numNullableArg, core::int intArg, core::int? intNullableArg, core::double doubleArg, core::double? doubleNullableArg, core::Function functionArg, core::Function? functionNullableArg, () → void toVoidArg, () →? void toVoidNullableArg, self::Tearoffable tearoffableArg, self::Tearoffable? tearoffableNullableArg, self::error::XnonNull xNonNullArg, self::error::XnonNull? xNonNullNullableArg, self::error::XpotentiallyNull% xPotentiallyNullArg, self::error::XpotentiallyNull? xPotentiallyNullNullableArg, self::error::YnonNull yNonNullArg, self::error::YnonNull? yNonNullNullableArg, self::error::YpotentiallyNull% yPotentiallyNullArg, self::error::YpotentiallyNull? yPotentiallyNullNullableArg) → dynamic {
+static method error<XnonNull extends core::Object, YnonNull extends self::error::XnonNull = core::Object, XpotentiallyNull extends core::Object?, YpotentiallyNull extends self::error::XpotentiallyNull% = core::Object?>(core::Object objectArg, core::Object? objectNullableArg, core::num numArg, core::num? numNullableArg, core::int intArg, core::int? intNullableArg, core::double doubleArg, core::double? doubleNullableArg, core::Function functionArg, core::Function? functionNullableArg, () → void toVoidArg, () →? void toVoidNullableArg, self::Tearoffable tearoffableArg, self::Tearoffable? tearoffableNullableArg, self::error::XnonNull xNonNullArg, self::error::XnonNull? xNonNullNullableArg, self::error::XpotentiallyNull% xPotentiallyNullArg, self::error::XpotentiallyNull? xPotentiallyNullNullableArg, self::error::YnonNull yNonNullArg, self::error::YnonNull? yNonNullNullableArg, self::error::YpotentiallyNull% yPotentiallyNullArg, self::error::YpotentiallyNull? yPotentiallyNullNullableArg) → dynamic {
   core::Object objectVar = let final Never #t3 = invalid-expression "pkg/front_end/testcases/nnbd/assignability.dart:114:22: Error: A value of type 'Object?' can't be assigned to a variable of type 'Object' because 'Object?' is nullable and 'Object' isn't.
  - 'Object' is from 'dart:core'.
   Object objectVar = objectNullableArg;
diff --git a/pkg/front_end/testcases/nnbd/assignability.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/assignability.dart.weak.outline.expect
index 5697d0b..a3a89d2 100644
--- a/pkg/front_end/testcases/nnbd/assignability.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/assignability.dart.weak.outline.expect
@@ -8,9 +8,9 @@
   method call() → void
     ;
 }
-static method ok<XnonNull extends core::Object = core::Object, YnonNull extends self::ok::XnonNull = core::Object, XpotentiallyNull extends core::Object? = core::Object?, YpotentiallyNull extends self::ok::XpotentiallyNull% = core::Object?>(dynamic dynamicArg, core::Object objectArg, core::num numArg, core::int intArg, core::double doubleArg, core::Function functionArg, () → void toVoidArg, self::Tearoffable tearoffableArg, self::ok::XnonNull xNonNullArg, self::ok::XpotentiallyNull% xPotentiallyNullArg, self::ok::YnonNull yNonNullArg, self::ok::YpotentiallyNull% yPotentiallyNullArg) → dynamic
+static method ok<XnonNull extends core::Object, YnonNull extends self::ok::XnonNull = core::Object, XpotentiallyNull extends core::Object?, YpotentiallyNull extends self::ok::XpotentiallyNull% = core::Object?>(dynamic dynamicArg, core::Object objectArg, core::num numArg, core::int intArg, core::double doubleArg, core::Function functionArg, () → void toVoidArg, self::Tearoffable tearoffableArg, self::ok::XnonNull xNonNullArg, self::ok::XpotentiallyNull% xPotentiallyNullArg, self::ok::YnonNull yNonNullArg, self::ok::YpotentiallyNull% yPotentiallyNullArg) → dynamic
   ;
-static method error<XnonNull extends core::Object = core::Object, YnonNull extends self::error::XnonNull = core::Object, XpotentiallyNull extends core::Object? = core::Object?, YpotentiallyNull extends self::error::XpotentiallyNull% = core::Object?>(core::Object objectArg, core::Object? objectNullableArg, core::num numArg, core::num? numNullableArg, core::int intArg, core::int? intNullableArg, core::double doubleArg, core::double? doubleNullableArg, core::Function functionArg, core::Function? functionNullableArg, () → void toVoidArg, () →? void toVoidNullableArg, self::Tearoffable tearoffableArg, self::Tearoffable? tearoffableNullableArg, self::error::XnonNull xNonNullArg, self::error::XnonNull? xNonNullNullableArg, self::error::XpotentiallyNull% xPotentiallyNullArg, self::error::XpotentiallyNull? xPotentiallyNullNullableArg, self::error::YnonNull yNonNullArg, self::error::YnonNull? yNonNullNullableArg, self::error::YpotentiallyNull% yPotentiallyNullArg, self::error::YpotentiallyNull? yPotentiallyNullNullableArg) → dynamic
+static method error<XnonNull extends core::Object, YnonNull extends self::error::XnonNull = core::Object, XpotentiallyNull extends core::Object?, YpotentiallyNull extends self::error::XpotentiallyNull% = core::Object?>(core::Object objectArg, core::Object? objectNullableArg, core::num numArg, core::num? numNullableArg, core::int intArg, core::int? intNullableArg, core::double doubleArg, core::double? doubleNullableArg, core::Function functionArg, core::Function? functionNullableArg, () → void toVoidArg, () →? void toVoidNullableArg, self::Tearoffable tearoffableArg, self::Tearoffable? tearoffableNullableArg, self::error::XnonNull xNonNullArg, self::error::XnonNull? xNonNullNullableArg, self::error::XpotentiallyNull% xPotentiallyNullArg, self::error::XpotentiallyNull? xPotentiallyNullNullableArg, self::error::YnonNull yNonNullArg, self::error::YnonNull? yNonNullNullableArg, self::error::YpotentiallyNull% yPotentiallyNullArg, self::error::YpotentiallyNull? yPotentiallyNullNullableArg) → dynamic
   ;
 static method main() → dynamic
   ;
diff --git a/pkg/front_end/testcases/nnbd/assignability.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/assignability.dart.weak.transformed.expect
index 74dd324..24484a9 100644
--- a/pkg/front_end/testcases/nnbd/assignability.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/assignability.dart.weak.transformed.expect
@@ -981,7 +981,7 @@
     ;
   method call() → void {}
 }
-static method ok<XnonNull extends core::Object = core::Object, YnonNull extends self::ok::XnonNull = core::Object, XpotentiallyNull extends core::Object? = core::Object?, YpotentiallyNull extends self::ok::XpotentiallyNull% = core::Object?>(dynamic dynamicArg, core::Object objectArg, core::num numArg, core::int intArg, core::double doubleArg, core::Function functionArg, () → void toVoidArg, self::Tearoffable tearoffableArg, self::ok::XnonNull xNonNullArg, self::ok::XpotentiallyNull% xPotentiallyNullArg, self::ok::YnonNull yNonNullArg, self::ok::YpotentiallyNull% yPotentiallyNullArg) → dynamic {
+static method ok<XnonNull extends core::Object, YnonNull extends self::ok::XnonNull = core::Object, XpotentiallyNull extends core::Object?, YpotentiallyNull extends self::ok::XpotentiallyNull% = core::Object?>(dynamic dynamicArg, core::Object objectArg, core::num numArg, core::int intArg, core::double doubleArg, core::Function functionArg, () → void toVoidArg, self::Tearoffable tearoffableArg, self::ok::XnonNull xNonNullArg, self::ok::XpotentiallyNull% xPotentiallyNullArg, self::ok::YnonNull yNonNullArg, self::ok::YpotentiallyNull% yPotentiallyNullArg) → dynamic {
   dynamic dynamicVar = dynamicArg;
   dynamicVar = objectArg;
   dynamicVar = numArg;
@@ -1031,7 +1031,7 @@
   self::ok::YpotentiallyNull% yPotentiallyNullVar = dynamicArg as{TypeError,ForDynamic,ForNonNullableByDefault} self::ok::YpotentiallyNull%;
   yPotentiallyNullVar = yPotentiallyNullArg;
 }
-static method error<XnonNull extends core::Object = core::Object, YnonNull extends self::error::XnonNull = core::Object, XpotentiallyNull extends core::Object? = core::Object?, YpotentiallyNull extends self::error::XpotentiallyNull% = core::Object?>(core::Object objectArg, core::Object? objectNullableArg, core::num numArg, core::num? numNullableArg, core::int intArg, core::int? intNullableArg, core::double doubleArg, core::double? doubleNullableArg, core::Function functionArg, core::Function? functionNullableArg, () → void toVoidArg, () →? void toVoidNullableArg, self::Tearoffable tearoffableArg, self::Tearoffable? tearoffableNullableArg, self::error::XnonNull xNonNullArg, self::error::XnonNull? xNonNullNullableArg, self::error::XpotentiallyNull% xPotentiallyNullArg, self::error::XpotentiallyNull? xPotentiallyNullNullableArg, self::error::YnonNull yNonNullArg, self::error::YnonNull? yNonNullNullableArg, self::error::YpotentiallyNull% yPotentiallyNullArg, self::error::YpotentiallyNull? yPotentiallyNullNullableArg) → dynamic {
+static method error<XnonNull extends core::Object, YnonNull extends self::error::XnonNull = core::Object, XpotentiallyNull extends core::Object?, YpotentiallyNull extends self::error::XpotentiallyNull% = core::Object?>(core::Object objectArg, core::Object? objectNullableArg, core::num numArg, core::num? numNullableArg, core::int intArg, core::int? intNullableArg, core::double doubleArg, core::double? doubleNullableArg, core::Function functionArg, core::Function? functionNullableArg, () → void toVoidArg, () →? void toVoidNullableArg, self::Tearoffable tearoffableArg, self::Tearoffable? tearoffableNullableArg, self::error::XnonNull xNonNullArg, self::error::XnonNull? xNonNullNullableArg, self::error::XpotentiallyNull% xPotentiallyNullArg, self::error::XpotentiallyNull? xPotentiallyNullNullableArg, self::error::YnonNull yNonNullArg, self::error::YnonNull? yNonNullNullableArg, self::error::YpotentiallyNull% yPotentiallyNullArg, self::error::YpotentiallyNull? yPotentiallyNullNullableArg) → dynamic {
   core::Object objectVar = let final Never #t3 = invalid-expression "pkg/front_end/testcases/nnbd/assignability.dart:114:22: Error: A value of type 'Object?' can't be assigned to a variable of type 'Object' because 'Object?' is nullable and 'Object' isn't.
  - 'Object' is from 'dart:core'.
   Object objectVar = objectNullableArg;
diff --git a/pkg/front_end/testcases/nnbd/bounds_checks.dart.strong.expect b/pkg/front_end/testcases/nnbd/bounds_checks.dart.strong.expect
index 90866e8..cf1774b 100644
--- a/pkg/front_end/testcases/nnbd/bounds_checks.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/bounds_checks.dart.strong.expect
@@ -59,7 +59,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<X extends core::num = core::num> extends core::Object {
+class A<X extends core::num> extends core::Object {
   synthetic constructor •() → self::A<self::A::X>
     : super core::Object::•()
     ;
@@ -69,7 +69,7 @@
     : super self::A::•()
     ;
 }
-class C<T extends self::A<core::num?> = self::A<core::num?>> extends core::Object {
+class C<T extends self::A<core::num?>> extends core::Object {
   synthetic constructor •() → self::C<self::C::T>
     : super core::Object::•()
     ;
@@ -78,12 +78,12 @@
   synthetic constructor •() → self::Hest
     : super core::Object::•()
     ;
-  method hest<T extends core::num = core::num>() → void {}
+  method hest<T extends core::num>() → void {}
 }
 static method foo(self::A<core::num?> a) → dynamic {}
 static method bar() → self::A<core::num?>? {}
-static method baz<T extends self::A<core::num?> = self::A<core::num?>>() → dynamic {}
-static method hest<T extends core::num = core::num>() → void {}
+static method baz<T extends self::A<core::num?>>() → dynamic {}
+static method hest<T extends core::num>() → void {}
 static method fisk(self::Hest h) → dynamic {
   self::hest<core::num?>();
   h.{self::Hest::hest}<core::num?>();
diff --git a/pkg/front_end/testcases/nnbd/bounds_checks.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/bounds_checks.dart.strong.transformed.expect
index 90866e8..cf1774b 100644
--- a/pkg/front_end/testcases/nnbd/bounds_checks.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/bounds_checks.dart.strong.transformed.expect
@@ -59,7 +59,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<X extends core::num = core::num> extends core::Object {
+class A<X extends core::num> extends core::Object {
   synthetic constructor •() → self::A<self::A::X>
     : super core::Object::•()
     ;
@@ -69,7 +69,7 @@
     : super self::A::•()
     ;
 }
-class C<T extends self::A<core::num?> = self::A<core::num?>> extends core::Object {
+class C<T extends self::A<core::num?>> extends core::Object {
   synthetic constructor •() → self::C<self::C::T>
     : super core::Object::•()
     ;
@@ -78,12 +78,12 @@
   synthetic constructor •() → self::Hest
     : super core::Object::•()
     ;
-  method hest<T extends core::num = core::num>() → void {}
+  method hest<T extends core::num>() → void {}
 }
 static method foo(self::A<core::num?> a) → dynamic {}
 static method bar() → self::A<core::num?>? {}
-static method baz<T extends self::A<core::num?> = self::A<core::num?>>() → dynamic {}
-static method hest<T extends core::num = core::num>() → void {}
+static method baz<T extends self::A<core::num?>>() → dynamic {}
+static method hest<T extends core::num>() → void {}
 static method fisk(self::Hest h) → dynamic {
   self::hest<core::num?>();
   h.{self::Hest::hest}<core::num?>();
diff --git a/pkg/front_end/testcases/nnbd/bounds_checks.dart.weak.expect b/pkg/front_end/testcases/nnbd/bounds_checks.dart.weak.expect
index 90866e8..cf1774b 100644
--- a/pkg/front_end/testcases/nnbd/bounds_checks.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/bounds_checks.dart.weak.expect
@@ -59,7 +59,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<X extends core::num = core::num> extends core::Object {
+class A<X extends core::num> extends core::Object {
   synthetic constructor •() → self::A<self::A::X>
     : super core::Object::•()
     ;
@@ -69,7 +69,7 @@
     : super self::A::•()
     ;
 }
-class C<T extends self::A<core::num?> = self::A<core::num?>> extends core::Object {
+class C<T extends self::A<core::num?>> extends core::Object {
   synthetic constructor •() → self::C<self::C::T>
     : super core::Object::•()
     ;
@@ -78,12 +78,12 @@
   synthetic constructor •() → self::Hest
     : super core::Object::•()
     ;
-  method hest<T extends core::num = core::num>() → void {}
+  method hest<T extends core::num>() → void {}
 }
 static method foo(self::A<core::num?> a) → dynamic {}
 static method bar() → self::A<core::num?>? {}
-static method baz<T extends self::A<core::num?> = self::A<core::num?>>() → dynamic {}
-static method hest<T extends core::num = core::num>() → void {}
+static method baz<T extends self::A<core::num?>>() → dynamic {}
+static method hest<T extends core::num>() → void {}
 static method fisk(self::Hest h) → dynamic {
   self::hest<core::num?>();
   h.{self::Hest::hest}<core::num?>();
diff --git a/pkg/front_end/testcases/nnbd/bounds_checks.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/bounds_checks.dart.weak.outline.expect
index f3c9fb6..be5c01e 100644
--- a/pkg/front_end/testcases/nnbd/bounds_checks.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/bounds_checks.dart.weak.outline.expect
@@ -45,7 +45,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<X extends core::num = core::num> extends core::Object {
+class A<X extends core::num> extends core::Object {
   synthetic constructor •() → self::A<self::A::X>
     ;
 }
@@ -53,23 +53,23 @@
   synthetic constructor •() → self::B
     ;
 }
-class C<T extends self::A<core::num?> = self::A<core::num?>> extends core::Object {
+class C<T extends self::A<core::num?>> extends core::Object {
   synthetic constructor •() → self::C<self::C::T>
     ;
 }
 class Hest extends core::Object {
   synthetic constructor •() → self::Hest
     ;
-  method hest<T extends core::num = core::num>() → void
+  method hest<T extends core::num>() → void
     ;
 }
 static method foo(self::A<core::num?> a) → dynamic
   ;
 static method bar() → self::A<core::num?>?
   ;
-static method baz<T extends self::A<core::num?> = self::A<core::num?>>() → dynamic
+static method baz<T extends self::A<core::num?>>() → dynamic
   ;
-static method hest<T extends core::num = core::num>() → void
+static method hest<T extends core::num>() → void
   ;
 static method fisk(self::Hest h) → dynamic
   ;
diff --git a/pkg/front_end/testcases/nnbd/bounds_checks.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/bounds_checks.dart.weak.transformed.expect
index 90866e8..cf1774b 100644
--- a/pkg/front_end/testcases/nnbd/bounds_checks.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/bounds_checks.dart.weak.transformed.expect
@@ -59,7 +59,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<X extends core::num = core::num> extends core::Object {
+class A<X extends core::num> extends core::Object {
   synthetic constructor •() → self::A<self::A::X>
     : super core::Object::•()
     ;
@@ -69,7 +69,7 @@
     : super self::A::•()
     ;
 }
-class C<T extends self::A<core::num?> = self::A<core::num?>> extends core::Object {
+class C<T extends self::A<core::num?>> extends core::Object {
   synthetic constructor •() → self::C<self::C::T>
     : super core::Object::•()
     ;
@@ -78,12 +78,12 @@
   synthetic constructor •() → self::Hest
     : super core::Object::•()
     ;
-  method hest<T extends core::num = core::num>() → void {}
+  method hest<T extends core::num>() → void {}
 }
 static method foo(self::A<core::num?> a) → dynamic {}
 static method bar() → self::A<core::num?>? {}
-static method baz<T extends self::A<core::num?> = self::A<core::num?>>() → dynamic {}
-static method hest<T extends core::num = core::num>() → void {}
+static method baz<T extends self::A<core::num?>>() → dynamic {}
+static method hest<T extends core::num>() → void {}
 static method fisk(self::Hest h) → dynamic {
   self::hest<core::num?>();
   h.{self::Hest::hest}<core::num?>();
diff --git a/pkg/front_end/testcases/nnbd/extension_bounds.dart.strong.expect b/pkg/front_end/testcases/nnbd/extension_bounds.dart.strong.expect
index c1de6b4..71679c9 100644
--- a/pkg/front_end/testcases/nnbd/extension_bounds.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/extension_bounds.dart.strong.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-extension Extension1<T extends core::Object = core::Object> on T {
+extension Extension1<T extends core::Object> on T {
   method method1 = self::Extension1|method1;
   tearoff method1 = self::Extension1|get#method1;
   method method2 = self::Extension1|method2;
@@ -14,7 +14,7 @@
   method method5 = self::Extension1|method5;
   tearoff method5 = self::Extension1|get#method5;
 }
-extension Extension2<T extends core::String = core::String> on T {
+extension Extension2<T extends core::String> on T {
   method method1 = self::Extension2|method1;
   tearoff method1 = self::Extension2|get#method1;
   method method2 = self::Extension2|method2;
@@ -26,7 +26,7 @@
   method method5 = self::Extension2|method5;
   tearoff method5 = self::Extension2|get#method5;
 }
-extension Extension3<T extends dynamic = dynamic> on T% {
+extension Extension3<T extends dynamic> on T% {
   method method1 = self::Extension3|method1;
   tearoff method1 = self::Extension3|get#method1;
   method method2 = self::Extension3|method2;
@@ -50,7 +50,7 @@
   method method5 = self::Extension4|method5;
   tearoff method5 = self::Extension4|get#method5;
 }
-extension Extension5<T extends core::Object? = core::Object?> on T% {
+extension Extension5<T extends core::Object?> on T% {
   method method1 = self::Extension5|method1;
   tearoff method1 = self::Extension5|get#method1;
   method method2 = self::Extension5|method2;
@@ -62,79 +62,79 @@
   method method5 = self::Extension5|method5;
   tearoff method5 = self::Extension5|get#method5;
 }
-static method Extension1|method1<T extends core::Object = core::Object, S extends core::Object = core::Object>(lowered final self::Extension1|method1::T #this) → dynamic {}
-static method Extension1|get#method1<T extends core::Object = core::Object>(lowered final self::Extension1|get#method1::T #this) → <S extends core::Object = core::Object>() → dynamic
-  return <S extends core::Object = core::Object>() → dynamic => self::Extension1|method1<self::Extension1|get#method1::T, S>(#this);
-static method Extension1|method2<T extends core::Object = core::Object, S extends core::String = core::String>(lowered final self::Extension1|method2::T #this) → dynamic {}
-static method Extension1|get#method2<T extends core::Object = core::Object>(lowered final self::Extension1|get#method2::T #this) → <S extends core::String = core::String>() → dynamic
-  return <S extends core::String = core::String>() → dynamic => self::Extension1|method2<self::Extension1|get#method2::T, S>(#this);
-static method Extension1|method3<T extends core::Object = core::Object, S extends dynamic = dynamic>(lowered final self::Extension1|method3::T #this) → dynamic {}
-static method Extension1|get#method3<T extends core::Object = core::Object>(lowered final self::Extension1|get#method3::T #this) → <S extends dynamic = dynamic>() → dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension1|method3<self::Extension1|get#method3::T, S%>(#this);
-static method Extension1|method4<T extends core::Object = core::Object, S extends core::Object? = dynamic>(lowered final self::Extension1|method4::T #this) → dynamic {}
-static method Extension1|get#method4<T extends core::Object = core::Object>(lowered final self::Extension1|get#method4::T #this) → <S extends core::Object? = dynamic>() → dynamic
+static method Extension1|method1<T extends core::Object, S extends core::Object>(lowered final self::Extension1|method1::T #this) → dynamic {}
+static method Extension1|get#method1<T extends core::Object>(lowered final self::Extension1|get#method1::T #this) → <S extends core::Object>() → dynamic
+  return <S extends core::Object>() → dynamic => self::Extension1|method1<self::Extension1|get#method1::T, S>(#this);
+static method Extension1|method2<T extends core::Object, S extends core::String>(lowered final self::Extension1|method2::T #this) → dynamic {}
+static method Extension1|get#method2<T extends core::Object>(lowered final self::Extension1|get#method2::T #this) → <S extends core::String>() → dynamic
+  return <S extends core::String>() → dynamic => self::Extension1|method2<self::Extension1|get#method2::T, S>(#this);
+static method Extension1|method3<T extends core::Object, S extends dynamic>(lowered final self::Extension1|method3::T #this) → dynamic {}
+static method Extension1|get#method3<T extends core::Object>(lowered final self::Extension1|get#method3::T #this) → <S extends dynamic>() → dynamic
+  return <S extends dynamic>() → dynamic => self::Extension1|method3<self::Extension1|get#method3::T, S%>(#this);
+static method Extension1|method4<T extends core::Object, S extends core::Object? = dynamic>(lowered final self::Extension1|method4::T #this) → dynamic {}
+static method Extension1|get#method4<T extends core::Object>(lowered final self::Extension1|get#method4::T #this) → <S extends core::Object? = dynamic>() → dynamic
   return <S extends core::Object? = dynamic>() → dynamic => self::Extension1|method4<self::Extension1|get#method4::T, S%>(#this);
-static method Extension1|method5<T extends core::Object = core::Object, S extends core::Object? = core::Object?>(lowered final self::Extension1|method5::T #this) → dynamic {}
-static method Extension1|get#method5<T extends core::Object = core::Object>(lowered final self::Extension1|get#method5::T #this) → <S extends core::Object? = core::Object?>() → dynamic
-  return <S extends core::Object? = core::Object?>() → dynamic => self::Extension1|method5<self::Extension1|get#method5::T, S%>(#this);
-static method Extension2|method1<T extends core::String = core::String, S extends core::Object = core::Object>(lowered final self::Extension2|method1::T #this) → dynamic {}
-static method Extension2|get#method1<T extends core::String = core::String>(lowered final self::Extension2|get#method1::T #this) → <S extends core::Object = core::Object>() → dynamic
-  return <S extends core::Object = core::Object>() → dynamic => self::Extension2|method1<self::Extension2|get#method1::T, S>(#this);
-static method Extension2|method2<T extends core::String = core::String, S extends core::String = core::String>(lowered final self::Extension2|method2::T #this) → dynamic {}
-static method Extension2|get#method2<T extends core::String = core::String>(lowered final self::Extension2|get#method2::T #this) → <S extends core::String = core::String>() → dynamic
-  return <S extends core::String = core::String>() → dynamic => self::Extension2|method2<self::Extension2|get#method2::T, S>(#this);
-static method Extension2|method3<T extends core::String = core::String, S extends dynamic = dynamic>(lowered final self::Extension2|method3::T #this) → dynamic {}
-static method Extension2|get#method3<T extends core::String = core::String>(lowered final self::Extension2|get#method3::T #this) → <S extends dynamic = dynamic>() → dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension2|method3<self::Extension2|get#method3::T, S%>(#this);
-static method Extension2|get#method4<T extends core::String = core::String>(lowered final self::Extension2|get#method4::T #this) → <S extends core::Object? = dynamic>() → dynamic
+static method Extension1|method5<T extends core::Object, S extends core::Object?>(lowered final self::Extension1|method5::T #this) → dynamic {}
+static method Extension1|get#method5<T extends core::Object>(lowered final self::Extension1|get#method5::T #this) → <S extends core::Object?>() → dynamic
+  return <S extends core::Object?>() → dynamic => self::Extension1|method5<self::Extension1|get#method5::T, S%>(#this);
+static method Extension2|method1<T extends core::String, S extends core::Object>(lowered final self::Extension2|method1::T #this) → dynamic {}
+static method Extension2|get#method1<T extends core::String>(lowered final self::Extension2|get#method1::T #this) → <S extends core::Object>() → dynamic
+  return <S extends core::Object>() → dynamic => self::Extension2|method1<self::Extension2|get#method1::T, S>(#this);
+static method Extension2|method2<T extends core::String, S extends core::String>(lowered final self::Extension2|method2::T #this) → dynamic {}
+static method Extension2|get#method2<T extends core::String>(lowered final self::Extension2|get#method2::T #this) → <S extends core::String>() → dynamic
+  return <S extends core::String>() → dynamic => self::Extension2|method2<self::Extension2|get#method2::T, S>(#this);
+static method Extension2|method3<T extends core::String, S extends dynamic>(lowered final self::Extension2|method3::T #this) → dynamic {}
+static method Extension2|get#method3<T extends core::String>(lowered final self::Extension2|get#method3::T #this) → <S extends dynamic>() → dynamic
+  return <S extends dynamic>() → dynamic => self::Extension2|method3<self::Extension2|get#method3::T, S%>(#this);
+static method Extension2|get#method4<T extends core::String>(lowered final self::Extension2|get#method4::T #this) → <S extends core::Object? = dynamic>() → dynamic
   return <S extends core::Object? = dynamic>() → dynamic => self::Extension2|method4<self::Extension2|get#method4::T, S%>(#this);
-static method Extension2|method4<T extends core::String = core::String, S extends core::Object? = dynamic>(lowered final self::Extension2|method4::T #this) → dynamic {}
-static method Extension2|method5<T extends core::String = core::String, S extends core::Object? = core::Object?>(lowered final self::Extension2|method5::T #this) → dynamic {}
-static method Extension2|get#method5<T extends core::String = core::String>(lowered final self::Extension2|get#method5::T #this) → <S extends core::Object? = core::Object?>() → dynamic
-  return <S extends core::Object? = core::Object?>() → dynamic => self::Extension2|method5<self::Extension2|get#method5::T, S%>(#this);
-static method Extension3|method1<T extends dynamic = dynamic, S extends core::Object = core::Object>(lowered final self::Extension3|method1::T% #this) → dynamic {}
-static method Extension3|get#method1<T extends dynamic = dynamic>(lowered final self::Extension3|get#method1::T% #this) → <S extends core::Object = core::Object>() → dynamic
-  return <S extends core::Object = core::Object>() → dynamic => self::Extension3|method1<self::Extension3|get#method1::T%, S>(#this);
-static method Extension3|method2<T extends dynamic = dynamic, S extends core::String = core::String>(lowered final self::Extension3|method2::T% #this) → dynamic {}
-static method Extension3|get#method2<T extends dynamic = dynamic>(lowered final self::Extension3|get#method2::T% #this) → <S extends core::String = core::String>() → dynamic
-  return <S extends core::String = core::String>() → dynamic => self::Extension3|method2<self::Extension3|get#method2::T%, S>(#this);
-static method Extension3|method3<T extends dynamic = dynamic, S extends dynamic = dynamic>(lowered final self::Extension3|method3::T% #this) → dynamic {}
-static method Extension3|get#method3<T extends dynamic = dynamic>(lowered final self::Extension3|get#method3::T% #this) → <S extends dynamic = dynamic>() → dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension3|method3<self::Extension3|get#method3::T%, S%>(#this);
-static method Extension3|method4<T extends dynamic = dynamic, S extends core::Object? = dynamic>(lowered final self::Extension3|method4::T% #this) → dynamic {}
-static method Extension3|get#method4<T extends dynamic = dynamic>(lowered final self::Extension3|get#method4::T% #this) → <S extends core::Object? = dynamic>() → dynamic
+static method Extension2|method4<T extends core::String, S extends core::Object? = dynamic>(lowered final self::Extension2|method4::T #this) → dynamic {}
+static method Extension2|method5<T extends core::String, S extends core::Object?>(lowered final self::Extension2|method5::T #this) → dynamic {}
+static method Extension2|get#method5<T extends core::String>(lowered final self::Extension2|get#method5::T #this) → <S extends core::Object?>() → dynamic
+  return <S extends core::Object?>() → dynamic => self::Extension2|method5<self::Extension2|get#method5::T, S%>(#this);
+static method Extension3|method1<T extends dynamic, S extends core::Object>(lowered final self::Extension3|method1::T% #this) → dynamic {}
+static method Extension3|get#method1<T extends dynamic>(lowered final self::Extension3|get#method1::T% #this) → <S extends core::Object>() → dynamic
+  return <S extends core::Object>() → dynamic => self::Extension3|method1<self::Extension3|get#method1::T%, S>(#this);
+static method Extension3|method2<T extends dynamic, S extends core::String>(lowered final self::Extension3|method2::T% #this) → dynamic {}
+static method Extension3|get#method2<T extends dynamic>(lowered final self::Extension3|get#method2::T% #this) → <S extends core::String>() → dynamic
+  return <S extends core::String>() → dynamic => self::Extension3|method2<self::Extension3|get#method2::T%, S>(#this);
+static method Extension3|method3<T extends dynamic, S extends dynamic>(lowered final self::Extension3|method3::T% #this) → dynamic {}
+static method Extension3|get#method3<T extends dynamic>(lowered final self::Extension3|get#method3::T% #this) → <S extends dynamic>() → dynamic
+  return <S extends dynamic>() → dynamic => self::Extension3|method3<self::Extension3|get#method3::T%, S%>(#this);
+static method Extension3|method4<T extends dynamic, S extends core::Object? = dynamic>(lowered final self::Extension3|method4::T% #this) → dynamic {}
+static method Extension3|get#method4<T extends dynamic>(lowered final self::Extension3|get#method4::T% #this) → <S extends core::Object? = dynamic>() → dynamic
   return <S extends core::Object? = dynamic>() → dynamic => self::Extension3|method4<self::Extension3|get#method4::T%, S%>(#this);
-static method Extension3|method5<T extends dynamic = dynamic, S extends core::Object? = core::Object?>(lowered final self::Extension3|method5::T% #this) → dynamic {}
-static method Extension3|get#method5<T extends dynamic = dynamic>(lowered final self::Extension3|get#method5::T% #this) → <S extends core::Object? = core::Object?>() → dynamic
-  return <S extends core::Object? = core::Object?>() → dynamic => self::Extension3|method5<self::Extension3|get#method5::T%, S%>(#this);
-static method Extension4|method1<T extends core::Object? = dynamic, S extends core::Object = core::Object>(lowered final self::Extension4|method1::T% #this) → dynamic {}
-static method Extension4|get#method1<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method1::T% #this) → <S extends core::Object = core::Object>() → dynamic
-  return <S extends core::Object = core::Object>() → dynamic => self::Extension4|method1<self::Extension4|get#method1::T%, S>(#this);
-static method Extension4|method2<T extends core::Object? = dynamic, S extends core::String = core::String>(lowered final self::Extension4|method2::T% #this) → dynamic {}
-static method Extension4|get#method2<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method2::T% #this) → <S extends core::String = core::String>() → dynamic
-  return <S extends core::String = core::String>() → dynamic => self::Extension4|method2<self::Extension4|get#method2::T%, S>(#this);
-static method Extension4|method3<T extends core::Object? = dynamic, S extends dynamic = dynamic>(lowered final self::Extension4|method3::T% #this) → dynamic {}
-static method Extension4|get#method3<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method3::T% #this) → <S extends dynamic = dynamic>() → dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension4|method3<self::Extension4|get#method3::T%, S%>(#this);
+static method Extension3|method5<T extends dynamic, S extends core::Object?>(lowered final self::Extension3|method5::T% #this) → dynamic {}
+static method Extension3|get#method5<T extends dynamic>(lowered final self::Extension3|get#method5::T% #this) → <S extends core::Object?>() → dynamic
+  return <S extends core::Object?>() → dynamic => self::Extension3|method5<self::Extension3|get#method5::T%, S%>(#this);
+static method Extension4|method1<T extends core::Object? = dynamic, S extends core::Object>(lowered final self::Extension4|method1::T% #this) → dynamic {}
+static method Extension4|get#method1<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method1::T% #this) → <S extends core::Object>() → dynamic
+  return <S extends core::Object>() → dynamic => self::Extension4|method1<self::Extension4|get#method1::T%, S>(#this);
+static method Extension4|method2<T extends core::Object? = dynamic, S extends core::String>(lowered final self::Extension4|method2::T% #this) → dynamic {}
+static method Extension4|get#method2<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method2::T% #this) → <S extends core::String>() → dynamic
+  return <S extends core::String>() → dynamic => self::Extension4|method2<self::Extension4|get#method2::T%, S>(#this);
+static method Extension4|method3<T extends core::Object? = dynamic, S extends dynamic>(lowered final self::Extension4|method3::T% #this) → dynamic {}
+static method Extension4|get#method3<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method3::T% #this) → <S extends dynamic>() → dynamic
+  return <S extends dynamic>() → dynamic => self::Extension4|method3<self::Extension4|get#method3::T%, S%>(#this);
 static method Extension4|method4<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(lowered final self::Extension4|method4::T% #this) → dynamic {}
 static method Extension4|get#method4<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method4::T% #this) → <S extends core::Object? = dynamic>() → dynamic
   return <S extends core::Object? = dynamic>() → dynamic => self::Extension4|method4<self::Extension4|get#method4::T%, S%>(#this);
-static method Extension4|method5<T extends core::Object? = dynamic, S extends core::Object? = core::Object?>(lowered final self::Extension4|method5::T% #this) → dynamic {}
-static method Extension4|get#method5<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method5::T% #this) → <S extends core::Object? = core::Object?>() → dynamic
-  return <S extends core::Object? = core::Object?>() → dynamic => self::Extension4|method5<self::Extension4|get#method5::T%, S%>(#this);
-static method Extension5|method1<T extends core::Object? = core::Object?, S extends core::Object = core::Object>(lowered final self::Extension5|method1::T% #this) → dynamic {}
-static method Extension5|get#method1<T extends core::Object? = core::Object?>(lowered final self::Extension5|get#method1::T% #this) → <S extends core::Object = core::Object>() → dynamic
-  return <S extends core::Object = core::Object>() → dynamic => self::Extension5|method1<self::Extension5|get#method1::T%, S>(#this);
-static method Extension5|method2<T extends core::Object? = core::Object?, S extends core::String = core::String>(lowered final self::Extension5|method2::T% #this) → dynamic {}
-static method Extension5|get#method2<T extends core::Object? = core::Object?>(lowered final self::Extension5|get#method2::T% #this) → <S extends core::String = core::String>() → dynamic
-  return <S extends core::String = core::String>() → dynamic => self::Extension5|method2<self::Extension5|get#method2::T%, S>(#this);
-static method Extension5|method3<T extends core::Object? = core::Object?, S extends dynamic = dynamic>(lowered final self::Extension5|method3::T% #this) → dynamic {}
-static method Extension5|get#method3<T extends core::Object? = core::Object?>(lowered final self::Extension5|get#method3::T% #this) → <S extends dynamic = dynamic>() → dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension5|method3<self::Extension5|get#method3::T%, S%>(#this);
-static method Extension5|method4<T extends core::Object? = core::Object?, S extends core::Object? = dynamic>(lowered final self::Extension5|method4::T% #this) → dynamic {}
-static method Extension5|get#method4<T extends core::Object? = core::Object?>(lowered final self::Extension5|get#method4::T% #this) → <S extends core::Object? = dynamic>() → dynamic
+static method Extension4|method5<T extends core::Object? = dynamic, S extends core::Object?>(lowered final self::Extension4|method5::T% #this) → dynamic {}
+static method Extension4|get#method5<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method5::T% #this) → <S extends core::Object?>() → dynamic
+  return <S extends core::Object?>() → dynamic => self::Extension4|method5<self::Extension4|get#method5::T%, S%>(#this);
+static method Extension5|method1<T extends core::Object?, S extends core::Object>(lowered final self::Extension5|method1::T% #this) → dynamic {}
+static method Extension5|get#method1<T extends core::Object?>(lowered final self::Extension5|get#method1::T% #this) → <S extends core::Object>() → dynamic
+  return <S extends core::Object>() → dynamic => self::Extension5|method1<self::Extension5|get#method1::T%, S>(#this);
+static method Extension5|method2<T extends core::Object?, S extends core::String>(lowered final self::Extension5|method2::T% #this) → dynamic {}
+static method Extension5|get#method2<T extends core::Object?>(lowered final self::Extension5|get#method2::T% #this) → <S extends core::String>() → dynamic
+  return <S extends core::String>() → dynamic => self::Extension5|method2<self::Extension5|get#method2::T%, S>(#this);
+static method Extension5|method3<T extends core::Object?, S extends dynamic>(lowered final self::Extension5|method3::T% #this) → dynamic {}
+static method Extension5|get#method3<T extends core::Object?>(lowered final self::Extension5|get#method3::T% #this) → <S extends dynamic>() → dynamic
+  return <S extends dynamic>() → dynamic => self::Extension5|method3<self::Extension5|get#method3::T%, S%>(#this);
+static method Extension5|method4<T extends core::Object?, S extends core::Object? = dynamic>(lowered final self::Extension5|method4::T% #this) → dynamic {}
+static method Extension5|get#method4<T extends core::Object?>(lowered final self::Extension5|get#method4::T% #this) → <S extends core::Object? = dynamic>() → dynamic
   return <S extends core::Object? = dynamic>() → dynamic => self::Extension5|method4<self::Extension5|get#method4::T%, S%>(#this);
-static method Extension5|method5<T extends core::Object? = core::Object?, S extends core::Object? = core::Object?>(lowered final self::Extension5|method5::T% #this) → dynamic {}
-static method Extension5|get#method5<T extends core::Object? = core::Object?>(lowered final self::Extension5|get#method5::T% #this) → <S extends core::Object? = core::Object?>() → dynamic
-  return <S extends core::Object? = core::Object?>() → dynamic => self::Extension5|method5<self::Extension5|get#method5::T%, S%>(#this);
+static method Extension5|method5<T extends core::Object?, S extends core::Object?>(lowered final self::Extension5|method5::T% #this) → dynamic {}
+static method Extension5|get#method5<T extends core::Object?>(lowered final self::Extension5|get#method5::T% #this) → <S extends core::Object?>() → dynamic
+  return <S extends core::Object?>() → dynamic => self::Extension5|method5<self::Extension5|get#method5::T%, S%>(#this);
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd/extension_bounds.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/extension_bounds.dart.strong.transformed.expect
index c1de6b4..71679c9 100644
--- a/pkg/front_end/testcases/nnbd/extension_bounds.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/extension_bounds.dart.strong.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-extension Extension1<T extends core::Object = core::Object> on T {
+extension Extension1<T extends core::Object> on T {
   method method1 = self::Extension1|method1;
   tearoff method1 = self::Extension1|get#method1;
   method method2 = self::Extension1|method2;
@@ -14,7 +14,7 @@
   method method5 = self::Extension1|method5;
   tearoff method5 = self::Extension1|get#method5;
 }
-extension Extension2<T extends core::String = core::String> on T {
+extension Extension2<T extends core::String> on T {
   method method1 = self::Extension2|method1;
   tearoff method1 = self::Extension2|get#method1;
   method method2 = self::Extension2|method2;
@@ -26,7 +26,7 @@
   method method5 = self::Extension2|method5;
   tearoff method5 = self::Extension2|get#method5;
 }
-extension Extension3<T extends dynamic = dynamic> on T% {
+extension Extension3<T extends dynamic> on T% {
   method method1 = self::Extension3|method1;
   tearoff method1 = self::Extension3|get#method1;
   method method2 = self::Extension3|method2;
@@ -50,7 +50,7 @@
   method method5 = self::Extension4|method5;
   tearoff method5 = self::Extension4|get#method5;
 }
-extension Extension5<T extends core::Object? = core::Object?> on T% {
+extension Extension5<T extends core::Object?> on T% {
   method method1 = self::Extension5|method1;
   tearoff method1 = self::Extension5|get#method1;
   method method2 = self::Extension5|method2;
@@ -62,79 +62,79 @@
   method method5 = self::Extension5|method5;
   tearoff method5 = self::Extension5|get#method5;
 }
-static method Extension1|method1<T extends core::Object = core::Object, S extends core::Object = core::Object>(lowered final self::Extension1|method1::T #this) → dynamic {}
-static method Extension1|get#method1<T extends core::Object = core::Object>(lowered final self::Extension1|get#method1::T #this) → <S extends core::Object = core::Object>() → dynamic
-  return <S extends core::Object = core::Object>() → dynamic => self::Extension1|method1<self::Extension1|get#method1::T, S>(#this);
-static method Extension1|method2<T extends core::Object = core::Object, S extends core::String = core::String>(lowered final self::Extension1|method2::T #this) → dynamic {}
-static method Extension1|get#method2<T extends core::Object = core::Object>(lowered final self::Extension1|get#method2::T #this) → <S extends core::String = core::String>() → dynamic
-  return <S extends core::String = core::String>() → dynamic => self::Extension1|method2<self::Extension1|get#method2::T, S>(#this);
-static method Extension1|method3<T extends core::Object = core::Object, S extends dynamic = dynamic>(lowered final self::Extension1|method3::T #this) → dynamic {}
-static method Extension1|get#method3<T extends core::Object = core::Object>(lowered final self::Extension1|get#method3::T #this) → <S extends dynamic = dynamic>() → dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension1|method3<self::Extension1|get#method3::T, S%>(#this);
-static method Extension1|method4<T extends core::Object = core::Object, S extends core::Object? = dynamic>(lowered final self::Extension1|method4::T #this) → dynamic {}
-static method Extension1|get#method4<T extends core::Object = core::Object>(lowered final self::Extension1|get#method4::T #this) → <S extends core::Object? = dynamic>() → dynamic
+static method Extension1|method1<T extends core::Object, S extends core::Object>(lowered final self::Extension1|method1::T #this) → dynamic {}
+static method Extension1|get#method1<T extends core::Object>(lowered final self::Extension1|get#method1::T #this) → <S extends core::Object>() → dynamic
+  return <S extends core::Object>() → dynamic => self::Extension1|method1<self::Extension1|get#method1::T, S>(#this);
+static method Extension1|method2<T extends core::Object, S extends core::String>(lowered final self::Extension1|method2::T #this) → dynamic {}
+static method Extension1|get#method2<T extends core::Object>(lowered final self::Extension1|get#method2::T #this) → <S extends core::String>() → dynamic
+  return <S extends core::String>() → dynamic => self::Extension1|method2<self::Extension1|get#method2::T, S>(#this);
+static method Extension1|method3<T extends core::Object, S extends dynamic>(lowered final self::Extension1|method3::T #this) → dynamic {}
+static method Extension1|get#method3<T extends core::Object>(lowered final self::Extension1|get#method3::T #this) → <S extends dynamic>() → dynamic
+  return <S extends dynamic>() → dynamic => self::Extension1|method3<self::Extension1|get#method3::T, S%>(#this);
+static method Extension1|method4<T extends core::Object, S extends core::Object? = dynamic>(lowered final self::Extension1|method4::T #this) → dynamic {}
+static method Extension1|get#method4<T extends core::Object>(lowered final self::Extension1|get#method4::T #this) → <S extends core::Object? = dynamic>() → dynamic
   return <S extends core::Object? = dynamic>() → dynamic => self::Extension1|method4<self::Extension1|get#method4::T, S%>(#this);
-static method Extension1|method5<T extends core::Object = core::Object, S extends core::Object? = core::Object?>(lowered final self::Extension1|method5::T #this) → dynamic {}
-static method Extension1|get#method5<T extends core::Object = core::Object>(lowered final self::Extension1|get#method5::T #this) → <S extends core::Object? = core::Object?>() → dynamic
-  return <S extends core::Object? = core::Object?>() → dynamic => self::Extension1|method5<self::Extension1|get#method5::T, S%>(#this);
-static method Extension2|method1<T extends core::String = core::String, S extends core::Object = core::Object>(lowered final self::Extension2|method1::T #this) → dynamic {}
-static method Extension2|get#method1<T extends core::String = core::String>(lowered final self::Extension2|get#method1::T #this) → <S extends core::Object = core::Object>() → dynamic
-  return <S extends core::Object = core::Object>() → dynamic => self::Extension2|method1<self::Extension2|get#method1::T, S>(#this);
-static method Extension2|method2<T extends core::String = core::String, S extends core::String = core::String>(lowered final self::Extension2|method2::T #this) → dynamic {}
-static method Extension2|get#method2<T extends core::String = core::String>(lowered final self::Extension2|get#method2::T #this) → <S extends core::String = core::String>() → dynamic
-  return <S extends core::String = core::String>() → dynamic => self::Extension2|method2<self::Extension2|get#method2::T, S>(#this);
-static method Extension2|method3<T extends core::String = core::String, S extends dynamic = dynamic>(lowered final self::Extension2|method3::T #this) → dynamic {}
-static method Extension2|get#method3<T extends core::String = core::String>(lowered final self::Extension2|get#method3::T #this) → <S extends dynamic = dynamic>() → dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension2|method3<self::Extension2|get#method3::T, S%>(#this);
-static method Extension2|get#method4<T extends core::String = core::String>(lowered final self::Extension2|get#method4::T #this) → <S extends core::Object? = dynamic>() → dynamic
+static method Extension1|method5<T extends core::Object, S extends core::Object?>(lowered final self::Extension1|method5::T #this) → dynamic {}
+static method Extension1|get#method5<T extends core::Object>(lowered final self::Extension1|get#method5::T #this) → <S extends core::Object?>() → dynamic
+  return <S extends core::Object?>() → dynamic => self::Extension1|method5<self::Extension1|get#method5::T, S%>(#this);
+static method Extension2|method1<T extends core::String, S extends core::Object>(lowered final self::Extension2|method1::T #this) → dynamic {}
+static method Extension2|get#method1<T extends core::String>(lowered final self::Extension2|get#method1::T #this) → <S extends core::Object>() → dynamic
+  return <S extends core::Object>() → dynamic => self::Extension2|method1<self::Extension2|get#method1::T, S>(#this);
+static method Extension2|method2<T extends core::String, S extends core::String>(lowered final self::Extension2|method2::T #this) → dynamic {}
+static method Extension2|get#method2<T extends core::String>(lowered final self::Extension2|get#method2::T #this) → <S extends core::String>() → dynamic
+  return <S extends core::String>() → dynamic => self::Extension2|method2<self::Extension2|get#method2::T, S>(#this);
+static method Extension2|method3<T extends core::String, S extends dynamic>(lowered final self::Extension2|method3::T #this) → dynamic {}
+static method Extension2|get#method3<T extends core::String>(lowered final self::Extension2|get#method3::T #this) → <S extends dynamic>() → dynamic
+  return <S extends dynamic>() → dynamic => self::Extension2|method3<self::Extension2|get#method3::T, S%>(#this);
+static method Extension2|get#method4<T extends core::String>(lowered final self::Extension2|get#method4::T #this) → <S extends core::Object? = dynamic>() → dynamic
   return <S extends core::Object? = dynamic>() → dynamic => self::Extension2|method4<self::Extension2|get#method4::T, S%>(#this);
-static method Extension2|method4<T extends core::String = core::String, S extends core::Object? = dynamic>(lowered final self::Extension2|method4::T #this) → dynamic {}
-static method Extension2|method5<T extends core::String = core::String, S extends core::Object? = core::Object?>(lowered final self::Extension2|method5::T #this) → dynamic {}
-static method Extension2|get#method5<T extends core::String = core::String>(lowered final self::Extension2|get#method5::T #this) → <S extends core::Object? = core::Object?>() → dynamic
-  return <S extends core::Object? = core::Object?>() → dynamic => self::Extension2|method5<self::Extension2|get#method5::T, S%>(#this);
-static method Extension3|method1<T extends dynamic = dynamic, S extends core::Object = core::Object>(lowered final self::Extension3|method1::T% #this) → dynamic {}
-static method Extension3|get#method1<T extends dynamic = dynamic>(lowered final self::Extension3|get#method1::T% #this) → <S extends core::Object = core::Object>() → dynamic
-  return <S extends core::Object = core::Object>() → dynamic => self::Extension3|method1<self::Extension3|get#method1::T%, S>(#this);
-static method Extension3|method2<T extends dynamic = dynamic, S extends core::String = core::String>(lowered final self::Extension3|method2::T% #this) → dynamic {}
-static method Extension3|get#method2<T extends dynamic = dynamic>(lowered final self::Extension3|get#method2::T% #this) → <S extends core::String = core::String>() → dynamic
-  return <S extends core::String = core::String>() → dynamic => self::Extension3|method2<self::Extension3|get#method2::T%, S>(#this);
-static method Extension3|method3<T extends dynamic = dynamic, S extends dynamic = dynamic>(lowered final self::Extension3|method3::T% #this) → dynamic {}
-static method Extension3|get#method3<T extends dynamic = dynamic>(lowered final self::Extension3|get#method3::T% #this) → <S extends dynamic = dynamic>() → dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension3|method3<self::Extension3|get#method3::T%, S%>(#this);
-static method Extension3|method4<T extends dynamic = dynamic, S extends core::Object? = dynamic>(lowered final self::Extension3|method4::T% #this) → dynamic {}
-static method Extension3|get#method4<T extends dynamic = dynamic>(lowered final self::Extension3|get#method4::T% #this) → <S extends core::Object? = dynamic>() → dynamic
+static method Extension2|method4<T extends core::String, S extends core::Object? = dynamic>(lowered final self::Extension2|method4::T #this) → dynamic {}
+static method Extension2|method5<T extends core::String, S extends core::Object?>(lowered final self::Extension2|method5::T #this) → dynamic {}
+static method Extension2|get#method5<T extends core::String>(lowered final self::Extension2|get#method5::T #this) → <S extends core::Object?>() → dynamic
+  return <S extends core::Object?>() → dynamic => self::Extension2|method5<self::Extension2|get#method5::T, S%>(#this);
+static method Extension3|method1<T extends dynamic, S extends core::Object>(lowered final self::Extension3|method1::T% #this) → dynamic {}
+static method Extension3|get#method1<T extends dynamic>(lowered final self::Extension3|get#method1::T% #this) → <S extends core::Object>() → dynamic
+  return <S extends core::Object>() → dynamic => self::Extension3|method1<self::Extension3|get#method1::T%, S>(#this);
+static method Extension3|method2<T extends dynamic, S extends core::String>(lowered final self::Extension3|method2::T% #this) → dynamic {}
+static method Extension3|get#method2<T extends dynamic>(lowered final self::Extension3|get#method2::T% #this) → <S extends core::String>() → dynamic
+  return <S extends core::String>() → dynamic => self::Extension3|method2<self::Extension3|get#method2::T%, S>(#this);
+static method Extension3|method3<T extends dynamic, S extends dynamic>(lowered final self::Extension3|method3::T% #this) → dynamic {}
+static method Extension3|get#method3<T extends dynamic>(lowered final self::Extension3|get#method3::T% #this) → <S extends dynamic>() → dynamic
+  return <S extends dynamic>() → dynamic => self::Extension3|method3<self::Extension3|get#method3::T%, S%>(#this);
+static method Extension3|method4<T extends dynamic, S extends core::Object? = dynamic>(lowered final self::Extension3|method4::T% #this) → dynamic {}
+static method Extension3|get#method4<T extends dynamic>(lowered final self::Extension3|get#method4::T% #this) → <S extends core::Object? = dynamic>() → dynamic
   return <S extends core::Object? = dynamic>() → dynamic => self::Extension3|method4<self::Extension3|get#method4::T%, S%>(#this);
-static method Extension3|method5<T extends dynamic = dynamic, S extends core::Object? = core::Object?>(lowered final self::Extension3|method5::T% #this) → dynamic {}
-static method Extension3|get#method5<T extends dynamic = dynamic>(lowered final self::Extension3|get#method5::T% #this) → <S extends core::Object? = core::Object?>() → dynamic
-  return <S extends core::Object? = core::Object?>() → dynamic => self::Extension3|method5<self::Extension3|get#method5::T%, S%>(#this);
-static method Extension4|method1<T extends core::Object? = dynamic, S extends core::Object = core::Object>(lowered final self::Extension4|method1::T% #this) → dynamic {}
-static method Extension4|get#method1<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method1::T% #this) → <S extends core::Object = core::Object>() → dynamic
-  return <S extends core::Object = core::Object>() → dynamic => self::Extension4|method1<self::Extension4|get#method1::T%, S>(#this);
-static method Extension4|method2<T extends core::Object? = dynamic, S extends core::String = core::String>(lowered final self::Extension4|method2::T% #this) → dynamic {}
-static method Extension4|get#method2<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method2::T% #this) → <S extends core::String = core::String>() → dynamic
-  return <S extends core::String = core::String>() → dynamic => self::Extension4|method2<self::Extension4|get#method2::T%, S>(#this);
-static method Extension4|method3<T extends core::Object? = dynamic, S extends dynamic = dynamic>(lowered final self::Extension4|method3::T% #this) → dynamic {}
-static method Extension4|get#method3<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method3::T% #this) → <S extends dynamic = dynamic>() → dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension4|method3<self::Extension4|get#method3::T%, S%>(#this);
+static method Extension3|method5<T extends dynamic, S extends core::Object?>(lowered final self::Extension3|method5::T% #this) → dynamic {}
+static method Extension3|get#method5<T extends dynamic>(lowered final self::Extension3|get#method5::T% #this) → <S extends core::Object?>() → dynamic
+  return <S extends core::Object?>() → dynamic => self::Extension3|method5<self::Extension3|get#method5::T%, S%>(#this);
+static method Extension4|method1<T extends core::Object? = dynamic, S extends core::Object>(lowered final self::Extension4|method1::T% #this) → dynamic {}
+static method Extension4|get#method1<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method1::T% #this) → <S extends core::Object>() → dynamic
+  return <S extends core::Object>() → dynamic => self::Extension4|method1<self::Extension4|get#method1::T%, S>(#this);
+static method Extension4|method2<T extends core::Object? = dynamic, S extends core::String>(lowered final self::Extension4|method2::T% #this) → dynamic {}
+static method Extension4|get#method2<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method2::T% #this) → <S extends core::String>() → dynamic
+  return <S extends core::String>() → dynamic => self::Extension4|method2<self::Extension4|get#method2::T%, S>(#this);
+static method Extension4|method3<T extends core::Object? = dynamic, S extends dynamic>(lowered final self::Extension4|method3::T% #this) → dynamic {}
+static method Extension4|get#method3<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method3::T% #this) → <S extends dynamic>() → dynamic
+  return <S extends dynamic>() → dynamic => self::Extension4|method3<self::Extension4|get#method3::T%, S%>(#this);
 static method Extension4|method4<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(lowered final self::Extension4|method4::T% #this) → dynamic {}
 static method Extension4|get#method4<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method4::T% #this) → <S extends core::Object? = dynamic>() → dynamic
   return <S extends core::Object? = dynamic>() → dynamic => self::Extension4|method4<self::Extension4|get#method4::T%, S%>(#this);
-static method Extension4|method5<T extends core::Object? = dynamic, S extends core::Object? = core::Object?>(lowered final self::Extension4|method5::T% #this) → dynamic {}
-static method Extension4|get#method5<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method5::T% #this) → <S extends core::Object? = core::Object?>() → dynamic
-  return <S extends core::Object? = core::Object?>() → dynamic => self::Extension4|method5<self::Extension4|get#method5::T%, S%>(#this);
-static method Extension5|method1<T extends core::Object? = core::Object?, S extends core::Object = core::Object>(lowered final self::Extension5|method1::T% #this) → dynamic {}
-static method Extension5|get#method1<T extends core::Object? = core::Object?>(lowered final self::Extension5|get#method1::T% #this) → <S extends core::Object = core::Object>() → dynamic
-  return <S extends core::Object = core::Object>() → dynamic => self::Extension5|method1<self::Extension5|get#method1::T%, S>(#this);
-static method Extension5|method2<T extends core::Object? = core::Object?, S extends core::String = core::String>(lowered final self::Extension5|method2::T% #this) → dynamic {}
-static method Extension5|get#method2<T extends core::Object? = core::Object?>(lowered final self::Extension5|get#method2::T% #this) → <S extends core::String = core::String>() → dynamic
-  return <S extends core::String = core::String>() → dynamic => self::Extension5|method2<self::Extension5|get#method2::T%, S>(#this);
-static method Extension5|method3<T extends core::Object? = core::Object?, S extends dynamic = dynamic>(lowered final self::Extension5|method3::T% #this) → dynamic {}
-static method Extension5|get#method3<T extends core::Object? = core::Object?>(lowered final self::Extension5|get#method3::T% #this) → <S extends dynamic = dynamic>() → dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension5|method3<self::Extension5|get#method3::T%, S%>(#this);
-static method Extension5|method4<T extends core::Object? = core::Object?, S extends core::Object? = dynamic>(lowered final self::Extension5|method4::T% #this) → dynamic {}
-static method Extension5|get#method4<T extends core::Object? = core::Object?>(lowered final self::Extension5|get#method4::T% #this) → <S extends core::Object? = dynamic>() → dynamic
+static method Extension4|method5<T extends core::Object? = dynamic, S extends core::Object?>(lowered final self::Extension4|method5::T% #this) → dynamic {}
+static method Extension4|get#method5<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method5::T% #this) → <S extends core::Object?>() → dynamic
+  return <S extends core::Object?>() → dynamic => self::Extension4|method5<self::Extension4|get#method5::T%, S%>(#this);
+static method Extension5|method1<T extends core::Object?, S extends core::Object>(lowered final self::Extension5|method1::T% #this) → dynamic {}
+static method Extension5|get#method1<T extends core::Object?>(lowered final self::Extension5|get#method1::T% #this) → <S extends core::Object>() → dynamic
+  return <S extends core::Object>() → dynamic => self::Extension5|method1<self::Extension5|get#method1::T%, S>(#this);
+static method Extension5|method2<T extends core::Object?, S extends core::String>(lowered final self::Extension5|method2::T% #this) → dynamic {}
+static method Extension5|get#method2<T extends core::Object?>(lowered final self::Extension5|get#method2::T% #this) → <S extends core::String>() → dynamic
+  return <S extends core::String>() → dynamic => self::Extension5|method2<self::Extension5|get#method2::T%, S>(#this);
+static method Extension5|method3<T extends core::Object?, S extends dynamic>(lowered final self::Extension5|method3::T% #this) → dynamic {}
+static method Extension5|get#method3<T extends core::Object?>(lowered final self::Extension5|get#method3::T% #this) → <S extends dynamic>() → dynamic
+  return <S extends dynamic>() → dynamic => self::Extension5|method3<self::Extension5|get#method3::T%, S%>(#this);
+static method Extension5|method4<T extends core::Object?, S extends core::Object? = dynamic>(lowered final self::Extension5|method4::T% #this) → dynamic {}
+static method Extension5|get#method4<T extends core::Object?>(lowered final self::Extension5|get#method4::T% #this) → <S extends core::Object? = dynamic>() → dynamic
   return <S extends core::Object? = dynamic>() → dynamic => self::Extension5|method4<self::Extension5|get#method4::T%, S%>(#this);
-static method Extension5|method5<T extends core::Object? = core::Object?, S extends core::Object? = core::Object?>(lowered final self::Extension5|method5::T% #this) → dynamic {}
-static method Extension5|get#method5<T extends core::Object? = core::Object?>(lowered final self::Extension5|get#method5::T% #this) → <S extends core::Object? = core::Object?>() → dynamic
-  return <S extends core::Object? = core::Object?>() → dynamic => self::Extension5|method5<self::Extension5|get#method5::T%, S%>(#this);
+static method Extension5|method5<T extends core::Object?, S extends core::Object?>(lowered final self::Extension5|method5::T% #this) → dynamic {}
+static method Extension5|get#method5<T extends core::Object?>(lowered final self::Extension5|get#method5::T% #this) → <S extends core::Object?>() → dynamic
+  return <S extends core::Object?>() → dynamic => self::Extension5|method5<self::Extension5|get#method5::T%, S%>(#this);
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd/extension_bounds.dart.weak.expect b/pkg/front_end/testcases/nnbd/extension_bounds.dart.weak.expect
index c1de6b4..71679c9 100644
--- a/pkg/front_end/testcases/nnbd/extension_bounds.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/extension_bounds.dart.weak.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-extension Extension1<T extends core::Object = core::Object> on T {
+extension Extension1<T extends core::Object> on T {
   method method1 = self::Extension1|method1;
   tearoff method1 = self::Extension1|get#method1;
   method method2 = self::Extension1|method2;
@@ -14,7 +14,7 @@
   method method5 = self::Extension1|method5;
   tearoff method5 = self::Extension1|get#method5;
 }
-extension Extension2<T extends core::String = core::String> on T {
+extension Extension2<T extends core::String> on T {
   method method1 = self::Extension2|method1;
   tearoff method1 = self::Extension2|get#method1;
   method method2 = self::Extension2|method2;
@@ -26,7 +26,7 @@
   method method5 = self::Extension2|method5;
   tearoff method5 = self::Extension2|get#method5;
 }
-extension Extension3<T extends dynamic = dynamic> on T% {
+extension Extension3<T extends dynamic> on T% {
   method method1 = self::Extension3|method1;
   tearoff method1 = self::Extension3|get#method1;
   method method2 = self::Extension3|method2;
@@ -50,7 +50,7 @@
   method method5 = self::Extension4|method5;
   tearoff method5 = self::Extension4|get#method5;
 }
-extension Extension5<T extends core::Object? = core::Object?> on T% {
+extension Extension5<T extends core::Object?> on T% {
   method method1 = self::Extension5|method1;
   tearoff method1 = self::Extension5|get#method1;
   method method2 = self::Extension5|method2;
@@ -62,79 +62,79 @@
   method method5 = self::Extension5|method5;
   tearoff method5 = self::Extension5|get#method5;
 }
-static method Extension1|method1<T extends core::Object = core::Object, S extends core::Object = core::Object>(lowered final self::Extension1|method1::T #this) → dynamic {}
-static method Extension1|get#method1<T extends core::Object = core::Object>(lowered final self::Extension1|get#method1::T #this) → <S extends core::Object = core::Object>() → dynamic
-  return <S extends core::Object = core::Object>() → dynamic => self::Extension1|method1<self::Extension1|get#method1::T, S>(#this);
-static method Extension1|method2<T extends core::Object = core::Object, S extends core::String = core::String>(lowered final self::Extension1|method2::T #this) → dynamic {}
-static method Extension1|get#method2<T extends core::Object = core::Object>(lowered final self::Extension1|get#method2::T #this) → <S extends core::String = core::String>() → dynamic
-  return <S extends core::String = core::String>() → dynamic => self::Extension1|method2<self::Extension1|get#method2::T, S>(#this);
-static method Extension1|method3<T extends core::Object = core::Object, S extends dynamic = dynamic>(lowered final self::Extension1|method3::T #this) → dynamic {}
-static method Extension1|get#method3<T extends core::Object = core::Object>(lowered final self::Extension1|get#method3::T #this) → <S extends dynamic = dynamic>() → dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension1|method3<self::Extension1|get#method3::T, S%>(#this);
-static method Extension1|method4<T extends core::Object = core::Object, S extends core::Object? = dynamic>(lowered final self::Extension1|method4::T #this) → dynamic {}
-static method Extension1|get#method4<T extends core::Object = core::Object>(lowered final self::Extension1|get#method4::T #this) → <S extends core::Object? = dynamic>() → dynamic
+static method Extension1|method1<T extends core::Object, S extends core::Object>(lowered final self::Extension1|method1::T #this) → dynamic {}
+static method Extension1|get#method1<T extends core::Object>(lowered final self::Extension1|get#method1::T #this) → <S extends core::Object>() → dynamic
+  return <S extends core::Object>() → dynamic => self::Extension1|method1<self::Extension1|get#method1::T, S>(#this);
+static method Extension1|method2<T extends core::Object, S extends core::String>(lowered final self::Extension1|method2::T #this) → dynamic {}
+static method Extension1|get#method2<T extends core::Object>(lowered final self::Extension1|get#method2::T #this) → <S extends core::String>() → dynamic
+  return <S extends core::String>() → dynamic => self::Extension1|method2<self::Extension1|get#method2::T, S>(#this);
+static method Extension1|method3<T extends core::Object, S extends dynamic>(lowered final self::Extension1|method3::T #this) → dynamic {}
+static method Extension1|get#method3<T extends core::Object>(lowered final self::Extension1|get#method3::T #this) → <S extends dynamic>() → dynamic
+  return <S extends dynamic>() → dynamic => self::Extension1|method3<self::Extension1|get#method3::T, S%>(#this);
+static method Extension1|method4<T extends core::Object, S extends core::Object? = dynamic>(lowered final self::Extension1|method4::T #this) → dynamic {}
+static method Extension1|get#method4<T extends core::Object>(lowered final self::Extension1|get#method4::T #this) → <S extends core::Object? = dynamic>() → dynamic
   return <S extends core::Object? = dynamic>() → dynamic => self::Extension1|method4<self::Extension1|get#method4::T, S%>(#this);
-static method Extension1|method5<T extends core::Object = core::Object, S extends core::Object? = core::Object?>(lowered final self::Extension1|method5::T #this) → dynamic {}
-static method Extension1|get#method5<T extends core::Object = core::Object>(lowered final self::Extension1|get#method5::T #this) → <S extends core::Object? = core::Object?>() → dynamic
-  return <S extends core::Object? = core::Object?>() → dynamic => self::Extension1|method5<self::Extension1|get#method5::T, S%>(#this);
-static method Extension2|method1<T extends core::String = core::String, S extends core::Object = core::Object>(lowered final self::Extension2|method1::T #this) → dynamic {}
-static method Extension2|get#method1<T extends core::String = core::String>(lowered final self::Extension2|get#method1::T #this) → <S extends core::Object = core::Object>() → dynamic
-  return <S extends core::Object = core::Object>() → dynamic => self::Extension2|method1<self::Extension2|get#method1::T, S>(#this);
-static method Extension2|method2<T extends core::String = core::String, S extends core::String = core::String>(lowered final self::Extension2|method2::T #this) → dynamic {}
-static method Extension2|get#method2<T extends core::String = core::String>(lowered final self::Extension2|get#method2::T #this) → <S extends core::String = core::String>() → dynamic
-  return <S extends core::String = core::String>() → dynamic => self::Extension2|method2<self::Extension2|get#method2::T, S>(#this);
-static method Extension2|method3<T extends core::String = core::String, S extends dynamic = dynamic>(lowered final self::Extension2|method3::T #this) → dynamic {}
-static method Extension2|get#method3<T extends core::String = core::String>(lowered final self::Extension2|get#method3::T #this) → <S extends dynamic = dynamic>() → dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension2|method3<self::Extension2|get#method3::T, S%>(#this);
-static method Extension2|get#method4<T extends core::String = core::String>(lowered final self::Extension2|get#method4::T #this) → <S extends core::Object? = dynamic>() → dynamic
+static method Extension1|method5<T extends core::Object, S extends core::Object?>(lowered final self::Extension1|method5::T #this) → dynamic {}
+static method Extension1|get#method5<T extends core::Object>(lowered final self::Extension1|get#method5::T #this) → <S extends core::Object?>() → dynamic
+  return <S extends core::Object?>() → dynamic => self::Extension1|method5<self::Extension1|get#method5::T, S%>(#this);
+static method Extension2|method1<T extends core::String, S extends core::Object>(lowered final self::Extension2|method1::T #this) → dynamic {}
+static method Extension2|get#method1<T extends core::String>(lowered final self::Extension2|get#method1::T #this) → <S extends core::Object>() → dynamic
+  return <S extends core::Object>() → dynamic => self::Extension2|method1<self::Extension2|get#method1::T, S>(#this);
+static method Extension2|method2<T extends core::String, S extends core::String>(lowered final self::Extension2|method2::T #this) → dynamic {}
+static method Extension2|get#method2<T extends core::String>(lowered final self::Extension2|get#method2::T #this) → <S extends core::String>() → dynamic
+  return <S extends core::String>() → dynamic => self::Extension2|method2<self::Extension2|get#method2::T, S>(#this);
+static method Extension2|method3<T extends core::String, S extends dynamic>(lowered final self::Extension2|method3::T #this) → dynamic {}
+static method Extension2|get#method3<T extends core::String>(lowered final self::Extension2|get#method3::T #this) → <S extends dynamic>() → dynamic
+  return <S extends dynamic>() → dynamic => self::Extension2|method3<self::Extension2|get#method3::T, S%>(#this);
+static method Extension2|get#method4<T extends core::String>(lowered final self::Extension2|get#method4::T #this) → <S extends core::Object? = dynamic>() → dynamic
   return <S extends core::Object? = dynamic>() → dynamic => self::Extension2|method4<self::Extension2|get#method4::T, S%>(#this);
-static method Extension2|method4<T extends core::String = core::String, S extends core::Object? = dynamic>(lowered final self::Extension2|method4::T #this) → dynamic {}
-static method Extension2|method5<T extends core::String = core::String, S extends core::Object? = core::Object?>(lowered final self::Extension2|method5::T #this) → dynamic {}
-static method Extension2|get#method5<T extends core::String = core::String>(lowered final self::Extension2|get#method5::T #this) → <S extends core::Object? = core::Object?>() → dynamic
-  return <S extends core::Object? = core::Object?>() → dynamic => self::Extension2|method5<self::Extension2|get#method5::T, S%>(#this);
-static method Extension3|method1<T extends dynamic = dynamic, S extends core::Object = core::Object>(lowered final self::Extension3|method1::T% #this) → dynamic {}
-static method Extension3|get#method1<T extends dynamic = dynamic>(lowered final self::Extension3|get#method1::T% #this) → <S extends core::Object = core::Object>() → dynamic
-  return <S extends core::Object = core::Object>() → dynamic => self::Extension3|method1<self::Extension3|get#method1::T%, S>(#this);
-static method Extension3|method2<T extends dynamic = dynamic, S extends core::String = core::String>(lowered final self::Extension3|method2::T% #this) → dynamic {}
-static method Extension3|get#method2<T extends dynamic = dynamic>(lowered final self::Extension3|get#method2::T% #this) → <S extends core::String = core::String>() → dynamic
-  return <S extends core::String = core::String>() → dynamic => self::Extension3|method2<self::Extension3|get#method2::T%, S>(#this);
-static method Extension3|method3<T extends dynamic = dynamic, S extends dynamic = dynamic>(lowered final self::Extension3|method3::T% #this) → dynamic {}
-static method Extension3|get#method3<T extends dynamic = dynamic>(lowered final self::Extension3|get#method3::T% #this) → <S extends dynamic = dynamic>() → dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension3|method3<self::Extension3|get#method3::T%, S%>(#this);
-static method Extension3|method4<T extends dynamic = dynamic, S extends core::Object? = dynamic>(lowered final self::Extension3|method4::T% #this) → dynamic {}
-static method Extension3|get#method4<T extends dynamic = dynamic>(lowered final self::Extension3|get#method4::T% #this) → <S extends core::Object? = dynamic>() → dynamic
+static method Extension2|method4<T extends core::String, S extends core::Object? = dynamic>(lowered final self::Extension2|method4::T #this) → dynamic {}
+static method Extension2|method5<T extends core::String, S extends core::Object?>(lowered final self::Extension2|method5::T #this) → dynamic {}
+static method Extension2|get#method5<T extends core::String>(lowered final self::Extension2|get#method5::T #this) → <S extends core::Object?>() → dynamic
+  return <S extends core::Object?>() → dynamic => self::Extension2|method5<self::Extension2|get#method5::T, S%>(#this);
+static method Extension3|method1<T extends dynamic, S extends core::Object>(lowered final self::Extension3|method1::T% #this) → dynamic {}
+static method Extension3|get#method1<T extends dynamic>(lowered final self::Extension3|get#method1::T% #this) → <S extends core::Object>() → dynamic
+  return <S extends core::Object>() → dynamic => self::Extension3|method1<self::Extension3|get#method1::T%, S>(#this);
+static method Extension3|method2<T extends dynamic, S extends core::String>(lowered final self::Extension3|method2::T% #this) → dynamic {}
+static method Extension3|get#method2<T extends dynamic>(lowered final self::Extension3|get#method2::T% #this) → <S extends core::String>() → dynamic
+  return <S extends core::String>() → dynamic => self::Extension3|method2<self::Extension3|get#method2::T%, S>(#this);
+static method Extension3|method3<T extends dynamic, S extends dynamic>(lowered final self::Extension3|method3::T% #this) → dynamic {}
+static method Extension3|get#method3<T extends dynamic>(lowered final self::Extension3|get#method3::T% #this) → <S extends dynamic>() → dynamic
+  return <S extends dynamic>() → dynamic => self::Extension3|method3<self::Extension3|get#method3::T%, S%>(#this);
+static method Extension3|method4<T extends dynamic, S extends core::Object? = dynamic>(lowered final self::Extension3|method4::T% #this) → dynamic {}
+static method Extension3|get#method4<T extends dynamic>(lowered final self::Extension3|get#method4::T% #this) → <S extends core::Object? = dynamic>() → dynamic
   return <S extends core::Object? = dynamic>() → dynamic => self::Extension3|method4<self::Extension3|get#method4::T%, S%>(#this);
-static method Extension3|method5<T extends dynamic = dynamic, S extends core::Object? = core::Object?>(lowered final self::Extension3|method5::T% #this) → dynamic {}
-static method Extension3|get#method5<T extends dynamic = dynamic>(lowered final self::Extension3|get#method5::T% #this) → <S extends core::Object? = core::Object?>() → dynamic
-  return <S extends core::Object? = core::Object?>() → dynamic => self::Extension3|method5<self::Extension3|get#method5::T%, S%>(#this);
-static method Extension4|method1<T extends core::Object? = dynamic, S extends core::Object = core::Object>(lowered final self::Extension4|method1::T% #this) → dynamic {}
-static method Extension4|get#method1<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method1::T% #this) → <S extends core::Object = core::Object>() → dynamic
-  return <S extends core::Object = core::Object>() → dynamic => self::Extension4|method1<self::Extension4|get#method1::T%, S>(#this);
-static method Extension4|method2<T extends core::Object? = dynamic, S extends core::String = core::String>(lowered final self::Extension4|method2::T% #this) → dynamic {}
-static method Extension4|get#method2<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method2::T% #this) → <S extends core::String = core::String>() → dynamic
-  return <S extends core::String = core::String>() → dynamic => self::Extension4|method2<self::Extension4|get#method2::T%, S>(#this);
-static method Extension4|method3<T extends core::Object? = dynamic, S extends dynamic = dynamic>(lowered final self::Extension4|method3::T% #this) → dynamic {}
-static method Extension4|get#method3<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method3::T% #this) → <S extends dynamic = dynamic>() → dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension4|method3<self::Extension4|get#method3::T%, S%>(#this);
+static method Extension3|method5<T extends dynamic, S extends core::Object?>(lowered final self::Extension3|method5::T% #this) → dynamic {}
+static method Extension3|get#method5<T extends dynamic>(lowered final self::Extension3|get#method5::T% #this) → <S extends core::Object?>() → dynamic
+  return <S extends core::Object?>() → dynamic => self::Extension3|method5<self::Extension3|get#method5::T%, S%>(#this);
+static method Extension4|method1<T extends core::Object? = dynamic, S extends core::Object>(lowered final self::Extension4|method1::T% #this) → dynamic {}
+static method Extension4|get#method1<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method1::T% #this) → <S extends core::Object>() → dynamic
+  return <S extends core::Object>() → dynamic => self::Extension4|method1<self::Extension4|get#method1::T%, S>(#this);
+static method Extension4|method2<T extends core::Object? = dynamic, S extends core::String>(lowered final self::Extension4|method2::T% #this) → dynamic {}
+static method Extension4|get#method2<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method2::T% #this) → <S extends core::String>() → dynamic
+  return <S extends core::String>() → dynamic => self::Extension4|method2<self::Extension4|get#method2::T%, S>(#this);
+static method Extension4|method3<T extends core::Object? = dynamic, S extends dynamic>(lowered final self::Extension4|method3::T% #this) → dynamic {}
+static method Extension4|get#method3<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method3::T% #this) → <S extends dynamic>() → dynamic
+  return <S extends dynamic>() → dynamic => self::Extension4|method3<self::Extension4|get#method3::T%, S%>(#this);
 static method Extension4|method4<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(lowered final self::Extension4|method4::T% #this) → dynamic {}
 static method Extension4|get#method4<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method4::T% #this) → <S extends core::Object? = dynamic>() → dynamic
   return <S extends core::Object? = dynamic>() → dynamic => self::Extension4|method4<self::Extension4|get#method4::T%, S%>(#this);
-static method Extension4|method5<T extends core::Object? = dynamic, S extends core::Object? = core::Object?>(lowered final self::Extension4|method5::T% #this) → dynamic {}
-static method Extension4|get#method5<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method5::T% #this) → <S extends core::Object? = core::Object?>() → dynamic
-  return <S extends core::Object? = core::Object?>() → dynamic => self::Extension4|method5<self::Extension4|get#method5::T%, S%>(#this);
-static method Extension5|method1<T extends core::Object? = core::Object?, S extends core::Object = core::Object>(lowered final self::Extension5|method1::T% #this) → dynamic {}
-static method Extension5|get#method1<T extends core::Object? = core::Object?>(lowered final self::Extension5|get#method1::T% #this) → <S extends core::Object = core::Object>() → dynamic
-  return <S extends core::Object = core::Object>() → dynamic => self::Extension5|method1<self::Extension5|get#method1::T%, S>(#this);
-static method Extension5|method2<T extends core::Object? = core::Object?, S extends core::String = core::String>(lowered final self::Extension5|method2::T% #this) → dynamic {}
-static method Extension5|get#method2<T extends core::Object? = core::Object?>(lowered final self::Extension5|get#method2::T% #this) → <S extends core::String = core::String>() → dynamic
-  return <S extends core::String = core::String>() → dynamic => self::Extension5|method2<self::Extension5|get#method2::T%, S>(#this);
-static method Extension5|method3<T extends core::Object? = core::Object?, S extends dynamic = dynamic>(lowered final self::Extension5|method3::T% #this) → dynamic {}
-static method Extension5|get#method3<T extends core::Object? = core::Object?>(lowered final self::Extension5|get#method3::T% #this) → <S extends dynamic = dynamic>() → dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension5|method3<self::Extension5|get#method3::T%, S%>(#this);
-static method Extension5|method4<T extends core::Object? = core::Object?, S extends core::Object? = dynamic>(lowered final self::Extension5|method4::T% #this) → dynamic {}
-static method Extension5|get#method4<T extends core::Object? = core::Object?>(lowered final self::Extension5|get#method4::T% #this) → <S extends core::Object? = dynamic>() → dynamic
+static method Extension4|method5<T extends core::Object? = dynamic, S extends core::Object?>(lowered final self::Extension4|method5::T% #this) → dynamic {}
+static method Extension4|get#method5<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method5::T% #this) → <S extends core::Object?>() → dynamic
+  return <S extends core::Object?>() → dynamic => self::Extension4|method5<self::Extension4|get#method5::T%, S%>(#this);
+static method Extension5|method1<T extends core::Object?, S extends core::Object>(lowered final self::Extension5|method1::T% #this) → dynamic {}
+static method Extension5|get#method1<T extends core::Object?>(lowered final self::Extension5|get#method1::T% #this) → <S extends core::Object>() → dynamic
+  return <S extends core::Object>() → dynamic => self::Extension5|method1<self::Extension5|get#method1::T%, S>(#this);
+static method Extension5|method2<T extends core::Object?, S extends core::String>(lowered final self::Extension5|method2::T% #this) → dynamic {}
+static method Extension5|get#method2<T extends core::Object?>(lowered final self::Extension5|get#method2::T% #this) → <S extends core::String>() → dynamic
+  return <S extends core::String>() → dynamic => self::Extension5|method2<self::Extension5|get#method2::T%, S>(#this);
+static method Extension5|method3<T extends core::Object?, S extends dynamic>(lowered final self::Extension5|method3::T% #this) → dynamic {}
+static method Extension5|get#method3<T extends core::Object?>(lowered final self::Extension5|get#method3::T% #this) → <S extends dynamic>() → dynamic
+  return <S extends dynamic>() → dynamic => self::Extension5|method3<self::Extension5|get#method3::T%, S%>(#this);
+static method Extension5|method4<T extends core::Object?, S extends core::Object? = dynamic>(lowered final self::Extension5|method4::T% #this) → dynamic {}
+static method Extension5|get#method4<T extends core::Object?>(lowered final self::Extension5|get#method4::T% #this) → <S extends core::Object? = dynamic>() → dynamic
   return <S extends core::Object? = dynamic>() → dynamic => self::Extension5|method4<self::Extension5|get#method4::T%, S%>(#this);
-static method Extension5|method5<T extends core::Object? = core::Object?, S extends core::Object? = core::Object?>(lowered final self::Extension5|method5::T% #this) → dynamic {}
-static method Extension5|get#method5<T extends core::Object? = core::Object?>(lowered final self::Extension5|get#method5::T% #this) → <S extends core::Object? = core::Object?>() → dynamic
-  return <S extends core::Object? = core::Object?>() → dynamic => self::Extension5|method5<self::Extension5|get#method5::T%, S%>(#this);
+static method Extension5|method5<T extends core::Object?, S extends core::Object?>(lowered final self::Extension5|method5::T% #this) → dynamic {}
+static method Extension5|get#method5<T extends core::Object?>(lowered final self::Extension5|get#method5::T% #this) → <S extends core::Object?>() → dynamic
+  return <S extends core::Object?>() → dynamic => self::Extension5|method5<self::Extension5|get#method5::T%, S%>(#this);
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd/extension_bounds.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/extension_bounds.dart.weak.outline.expect
index 6cec804..848fec8 100644
--- a/pkg/front_end/testcases/nnbd/extension_bounds.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/extension_bounds.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-extension Extension1<T extends core::Object = core::Object> on T {
+extension Extension1<T extends core::Object> on T {
   method method1 = self::Extension1|method1;
   tearoff method1 = self::Extension1|get#method1;
   method method2 = self::Extension1|method2;
@@ -14,7 +14,7 @@
   method method5 = self::Extension1|method5;
   tearoff method5 = self::Extension1|get#method5;
 }
-extension Extension2<T extends core::String = core::String> on T {
+extension Extension2<T extends core::String> on T {
   method method1 = self::Extension2|method1;
   tearoff method1 = self::Extension2|get#method1;
   method method2 = self::Extension2|method2;
@@ -26,7 +26,7 @@
   method method5 = self::Extension2|method5;
   tearoff method5 = self::Extension2|get#method5;
 }
-extension Extension3<T extends dynamic = dynamic> on T% {
+extension Extension3<T extends dynamic> on T% {
   method method1 = self::Extension3|method1;
   tearoff method1 = self::Extension3|get#method1;
   method method2 = self::Extension3|method2;
@@ -50,7 +50,7 @@
   method method5 = self::Extension4|method5;
   tearoff method5 = self::Extension4|get#method5;
 }
-extension Extension5<T extends core::Object? = core::Object?> on T% {
+extension Extension5<T extends core::Object?> on T% {
   method method1 = self::Extension5|method1;
   tearoff method1 = self::Extension5|get#method1;
   method method2 = self::Extension5|method2;
@@ -62,105 +62,105 @@
   method method5 = self::Extension5|method5;
   tearoff method5 = self::Extension5|get#method5;
 }
-static method Extension1|method1<T extends core::Object = core::Object, S extends core::Object = core::Object>(lowered final self::Extension1|method1::T #this) → dynamic
+static method Extension1|method1<T extends core::Object, S extends core::Object>(lowered final self::Extension1|method1::T #this) → dynamic
   ;
-static method Extension1|get#method1<T extends core::Object = core::Object>(lowered final self::Extension1|get#method1::T #this) → <S extends core::Object = core::Object>() → dynamic
-  return <S extends core::Object = core::Object>() → dynamic => self::Extension1|method1<self::Extension1|get#method1::T, S>(#this);
-static method Extension1|method2<T extends core::Object = core::Object, S extends core::String = core::String>(lowered final self::Extension1|method2::T #this) → dynamic
+static method Extension1|get#method1<T extends core::Object>(lowered final self::Extension1|get#method1::T #this) → <S extends core::Object>() → dynamic
+  return <S extends core::Object>() → dynamic => self::Extension1|method1<self::Extension1|get#method1::T, S>(#this);
+static method Extension1|method2<T extends core::Object, S extends core::String>(lowered final self::Extension1|method2::T #this) → dynamic
   ;
-static method Extension1|get#method2<T extends core::Object = core::Object>(lowered final self::Extension1|get#method2::T #this) → <S extends core::String = core::String>() → dynamic
-  return <S extends core::String = core::String>() → dynamic => self::Extension1|method2<self::Extension1|get#method2::T, S>(#this);
-static method Extension1|method3<T extends core::Object = core::Object, S extends dynamic = dynamic>(lowered final self::Extension1|method3::T #this) → dynamic
+static method Extension1|get#method2<T extends core::Object>(lowered final self::Extension1|get#method2::T #this) → <S extends core::String>() → dynamic
+  return <S extends core::String>() → dynamic => self::Extension1|method2<self::Extension1|get#method2::T, S>(#this);
+static method Extension1|method3<T extends core::Object, S extends dynamic>(lowered final self::Extension1|method3::T #this) → dynamic
   ;
-static method Extension1|get#method3<T extends core::Object = core::Object>(lowered final self::Extension1|get#method3::T #this) → <S extends dynamic = dynamic>() → dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension1|method3<self::Extension1|get#method3::T, S%>(#this);
-static method Extension1|method4<T extends core::Object = core::Object, S extends core::Object? = dynamic>(lowered final self::Extension1|method4::T #this) → dynamic
+static method Extension1|get#method3<T extends core::Object>(lowered final self::Extension1|get#method3::T #this) → <S extends dynamic>() → dynamic
+  return <S extends dynamic>() → dynamic => self::Extension1|method3<self::Extension1|get#method3::T, S%>(#this);
+static method Extension1|method4<T extends core::Object, S extends core::Object? = dynamic>(lowered final self::Extension1|method4::T #this) → dynamic
   ;
-static method Extension1|get#method4<T extends core::Object = core::Object>(lowered final self::Extension1|get#method4::T #this) → <S extends core::Object? = dynamic>() → dynamic
+static method Extension1|get#method4<T extends core::Object>(lowered final self::Extension1|get#method4::T #this) → <S extends core::Object? = dynamic>() → dynamic
   return <S extends core::Object? = dynamic>() → dynamic => self::Extension1|method4<self::Extension1|get#method4::T, S%>(#this);
-static method Extension1|method5<T extends core::Object = core::Object, S extends core::Object? = core::Object?>(lowered final self::Extension1|method5::T #this) → dynamic
+static method Extension1|method5<T extends core::Object, S extends core::Object?>(lowered final self::Extension1|method5::T #this) → dynamic
   ;
-static method Extension1|get#method5<T extends core::Object = core::Object>(lowered final self::Extension1|get#method5::T #this) → <S extends core::Object? = core::Object?>() → dynamic
-  return <S extends core::Object? = core::Object?>() → dynamic => self::Extension1|method5<self::Extension1|get#method5::T, S%>(#this);
-static method Extension2|method1<T extends core::String = core::String, S extends core::Object = core::Object>(lowered final self::Extension2|method1::T #this) → dynamic
+static method Extension1|get#method5<T extends core::Object>(lowered final self::Extension1|get#method5::T #this) → <S extends core::Object?>() → dynamic
+  return <S extends core::Object?>() → dynamic => self::Extension1|method5<self::Extension1|get#method5::T, S%>(#this);
+static method Extension2|method1<T extends core::String, S extends core::Object>(lowered final self::Extension2|method1::T #this) → dynamic
   ;
-static method Extension2|get#method1<T extends core::String = core::String>(lowered final self::Extension2|get#method1::T #this) → <S extends core::Object = core::Object>() → dynamic
-  return <S extends core::Object = core::Object>() → dynamic => self::Extension2|method1<self::Extension2|get#method1::T, S>(#this);
-static method Extension2|method2<T extends core::String = core::String, S extends core::String = core::String>(lowered final self::Extension2|method2::T #this) → dynamic
+static method Extension2|get#method1<T extends core::String>(lowered final self::Extension2|get#method1::T #this) → <S extends core::Object>() → dynamic
+  return <S extends core::Object>() → dynamic => self::Extension2|method1<self::Extension2|get#method1::T, S>(#this);
+static method Extension2|method2<T extends core::String, S extends core::String>(lowered final self::Extension2|method2::T #this) → dynamic
   ;
-static method Extension2|get#method2<T extends core::String = core::String>(lowered final self::Extension2|get#method2::T #this) → <S extends core::String = core::String>() → dynamic
-  return <S extends core::String = core::String>() → dynamic => self::Extension2|method2<self::Extension2|get#method2::T, S>(#this);
-static method Extension2|method3<T extends core::String = core::String, S extends dynamic = dynamic>(lowered final self::Extension2|method3::T #this) → dynamic
+static method Extension2|get#method2<T extends core::String>(lowered final self::Extension2|get#method2::T #this) → <S extends core::String>() → dynamic
+  return <S extends core::String>() → dynamic => self::Extension2|method2<self::Extension2|get#method2::T, S>(#this);
+static method Extension2|method3<T extends core::String, S extends dynamic>(lowered final self::Extension2|method3::T #this) → dynamic
   ;
-static method Extension2|get#method3<T extends core::String = core::String>(lowered final self::Extension2|get#method3::T #this) → <S extends dynamic = dynamic>() → dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension2|method3<self::Extension2|get#method3::T, S%>(#this);
-static method Extension2|get#method4<T extends core::String = core::String>(lowered final self::Extension2|get#method4::T #this) → <S extends core::Object? = dynamic>() → dynamic
+static method Extension2|get#method3<T extends core::String>(lowered final self::Extension2|get#method3::T #this) → <S extends dynamic>() → dynamic
+  return <S extends dynamic>() → dynamic => self::Extension2|method3<self::Extension2|get#method3::T, S%>(#this);
+static method Extension2|get#method4<T extends core::String>(lowered final self::Extension2|get#method4::T #this) → <S extends core::Object? = dynamic>() → dynamic
   return <S extends core::Object? = dynamic>() → dynamic => self::Extension2|method4<self::Extension2|get#method4::T, S%>(#this);
-static method Extension2|method4<T extends core::String = core::String, S extends core::Object? = dynamic>(lowered final self::Extension2|method4::T #this) → dynamic
+static method Extension2|method4<T extends core::String, S extends core::Object? = dynamic>(lowered final self::Extension2|method4::T #this) → dynamic
   ;
-static method Extension2|method5<T extends core::String = core::String, S extends core::Object? = core::Object?>(lowered final self::Extension2|method5::T #this) → dynamic
+static method Extension2|method5<T extends core::String, S extends core::Object?>(lowered final self::Extension2|method5::T #this) → dynamic
   ;
-static method Extension2|get#method5<T extends core::String = core::String>(lowered final self::Extension2|get#method5::T #this) → <S extends core::Object? = core::Object?>() → dynamic
-  return <S extends core::Object? = core::Object?>() → dynamic => self::Extension2|method5<self::Extension2|get#method5::T, S%>(#this);
-static method Extension3|method1<T extends dynamic = dynamic, S extends core::Object = core::Object>(lowered final self::Extension3|method1::T% #this) → dynamic
+static method Extension2|get#method5<T extends core::String>(lowered final self::Extension2|get#method5::T #this) → <S extends core::Object?>() → dynamic
+  return <S extends core::Object?>() → dynamic => self::Extension2|method5<self::Extension2|get#method5::T, S%>(#this);
+static method Extension3|method1<T extends dynamic, S extends core::Object>(lowered final self::Extension3|method1::T% #this) → dynamic
   ;
-static method Extension3|get#method1<T extends dynamic = dynamic>(lowered final self::Extension3|get#method1::T% #this) → <S extends core::Object = core::Object>() → dynamic
-  return <S extends core::Object = core::Object>() → dynamic => self::Extension3|method1<self::Extension3|get#method1::T%, S>(#this);
-static method Extension3|method2<T extends dynamic = dynamic, S extends core::String = core::String>(lowered final self::Extension3|method2::T% #this) → dynamic
+static method Extension3|get#method1<T extends dynamic>(lowered final self::Extension3|get#method1::T% #this) → <S extends core::Object>() → dynamic
+  return <S extends core::Object>() → dynamic => self::Extension3|method1<self::Extension3|get#method1::T%, S>(#this);
+static method Extension3|method2<T extends dynamic, S extends core::String>(lowered final self::Extension3|method2::T% #this) → dynamic
   ;
-static method Extension3|get#method2<T extends dynamic = dynamic>(lowered final self::Extension3|get#method2::T% #this) → <S extends core::String = core::String>() → dynamic
-  return <S extends core::String = core::String>() → dynamic => self::Extension3|method2<self::Extension3|get#method2::T%, S>(#this);
-static method Extension3|method3<T extends dynamic = dynamic, S extends dynamic = dynamic>(lowered final self::Extension3|method3::T% #this) → dynamic
+static method Extension3|get#method2<T extends dynamic>(lowered final self::Extension3|get#method2::T% #this) → <S extends core::String>() → dynamic
+  return <S extends core::String>() → dynamic => self::Extension3|method2<self::Extension3|get#method2::T%, S>(#this);
+static method Extension3|method3<T extends dynamic, S extends dynamic>(lowered final self::Extension3|method3::T% #this) → dynamic
   ;
-static method Extension3|get#method3<T extends dynamic = dynamic>(lowered final self::Extension3|get#method3::T% #this) → <S extends dynamic = dynamic>() → dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension3|method3<self::Extension3|get#method3::T%, S%>(#this);
-static method Extension3|method4<T extends dynamic = dynamic, S extends core::Object? = dynamic>(lowered final self::Extension3|method4::T% #this) → dynamic
+static method Extension3|get#method3<T extends dynamic>(lowered final self::Extension3|get#method3::T% #this) → <S extends dynamic>() → dynamic
+  return <S extends dynamic>() → dynamic => self::Extension3|method3<self::Extension3|get#method3::T%, S%>(#this);
+static method Extension3|method4<T extends dynamic, S extends core::Object? = dynamic>(lowered final self::Extension3|method4::T% #this) → dynamic
   ;
-static method Extension3|get#method4<T extends dynamic = dynamic>(lowered final self::Extension3|get#method4::T% #this) → <S extends core::Object? = dynamic>() → dynamic
+static method Extension3|get#method4<T extends dynamic>(lowered final self::Extension3|get#method4::T% #this) → <S extends core::Object? = dynamic>() → dynamic
   return <S extends core::Object? = dynamic>() → dynamic => self::Extension3|method4<self::Extension3|get#method4::T%, S%>(#this);
-static method Extension3|method5<T extends dynamic = dynamic, S extends core::Object? = core::Object?>(lowered final self::Extension3|method5::T% #this) → dynamic
+static method Extension3|method5<T extends dynamic, S extends core::Object?>(lowered final self::Extension3|method5::T% #this) → dynamic
   ;
-static method Extension3|get#method5<T extends dynamic = dynamic>(lowered final self::Extension3|get#method5::T% #this) → <S extends core::Object? = core::Object?>() → dynamic
-  return <S extends core::Object? = core::Object?>() → dynamic => self::Extension3|method5<self::Extension3|get#method5::T%, S%>(#this);
-static method Extension4|method1<T extends core::Object? = dynamic, S extends core::Object = core::Object>(lowered final self::Extension4|method1::T% #this) → dynamic
+static method Extension3|get#method5<T extends dynamic>(lowered final self::Extension3|get#method5::T% #this) → <S extends core::Object?>() → dynamic
+  return <S extends core::Object?>() → dynamic => self::Extension3|method5<self::Extension3|get#method5::T%, S%>(#this);
+static method Extension4|method1<T extends core::Object? = dynamic, S extends core::Object>(lowered final self::Extension4|method1::T% #this) → dynamic
   ;
-static method Extension4|get#method1<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method1::T% #this) → <S extends core::Object = core::Object>() → dynamic
-  return <S extends core::Object = core::Object>() → dynamic => self::Extension4|method1<self::Extension4|get#method1::T%, S>(#this);
-static method Extension4|method2<T extends core::Object? = dynamic, S extends core::String = core::String>(lowered final self::Extension4|method2::T% #this) → dynamic
+static method Extension4|get#method1<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method1::T% #this) → <S extends core::Object>() → dynamic
+  return <S extends core::Object>() → dynamic => self::Extension4|method1<self::Extension4|get#method1::T%, S>(#this);
+static method Extension4|method2<T extends core::Object? = dynamic, S extends core::String>(lowered final self::Extension4|method2::T% #this) → dynamic
   ;
-static method Extension4|get#method2<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method2::T% #this) → <S extends core::String = core::String>() → dynamic
-  return <S extends core::String = core::String>() → dynamic => self::Extension4|method2<self::Extension4|get#method2::T%, S>(#this);
-static method Extension4|method3<T extends core::Object? = dynamic, S extends dynamic = dynamic>(lowered final self::Extension4|method3::T% #this) → dynamic
+static method Extension4|get#method2<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method2::T% #this) → <S extends core::String>() → dynamic
+  return <S extends core::String>() → dynamic => self::Extension4|method2<self::Extension4|get#method2::T%, S>(#this);
+static method Extension4|method3<T extends core::Object? = dynamic, S extends dynamic>(lowered final self::Extension4|method3::T% #this) → dynamic
   ;
-static method Extension4|get#method3<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method3::T% #this) → <S extends dynamic = dynamic>() → dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension4|method3<self::Extension4|get#method3::T%, S%>(#this);
+static method Extension4|get#method3<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method3::T% #this) → <S extends dynamic>() → dynamic
+  return <S extends dynamic>() → dynamic => self::Extension4|method3<self::Extension4|get#method3::T%, S%>(#this);
 static method Extension4|method4<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(lowered final self::Extension4|method4::T% #this) → dynamic
   ;
 static method Extension4|get#method4<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method4::T% #this) → <S extends core::Object? = dynamic>() → dynamic
   return <S extends core::Object? = dynamic>() → dynamic => self::Extension4|method4<self::Extension4|get#method4::T%, S%>(#this);
-static method Extension4|method5<T extends core::Object? = dynamic, S extends core::Object? = core::Object?>(lowered final self::Extension4|method5::T% #this) → dynamic
+static method Extension4|method5<T extends core::Object? = dynamic, S extends core::Object?>(lowered final self::Extension4|method5::T% #this) → dynamic
   ;
-static method Extension4|get#method5<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method5::T% #this) → <S extends core::Object? = core::Object?>() → dynamic
-  return <S extends core::Object? = core::Object?>() → dynamic => self::Extension4|method5<self::Extension4|get#method5::T%, S%>(#this);
-static method Extension5|method1<T extends core::Object? = core::Object?, S extends core::Object = core::Object>(lowered final self::Extension5|method1::T% #this) → dynamic
+static method Extension4|get#method5<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method5::T% #this) → <S extends core::Object?>() → dynamic
+  return <S extends core::Object?>() → dynamic => self::Extension4|method5<self::Extension4|get#method5::T%, S%>(#this);
+static method Extension5|method1<T extends core::Object?, S extends core::Object>(lowered final self::Extension5|method1::T% #this) → dynamic
   ;
-static method Extension5|get#method1<T extends core::Object? = core::Object?>(lowered final self::Extension5|get#method1::T% #this) → <S extends core::Object = core::Object>() → dynamic
-  return <S extends core::Object = core::Object>() → dynamic => self::Extension5|method1<self::Extension5|get#method1::T%, S>(#this);
-static method Extension5|method2<T extends core::Object? = core::Object?, S extends core::String = core::String>(lowered final self::Extension5|method2::T% #this) → dynamic
+static method Extension5|get#method1<T extends core::Object?>(lowered final self::Extension5|get#method1::T% #this) → <S extends core::Object>() → dynamic
+  return <S extends core::Object>() → dynamic => self::Extension5|method1<self::Extension5|get#method1::T%, S>(#this);
+static method Extension5|method2<T extends core::Object?, S extends core::String>(lowered final self::Extension5|method2::T% #this) → dynamic
   ;
-static method Extension5|get#method2<T extends core::Object? = core::Object?>(lowered final self::Extension5|get#method2::T% #this) → <S extends core::String = core::String>() → dynamic
-  return <S extends core::String = core::String>() → dynamic => self::Extension5|method2<self::Extension5|get#method2::T%, S>(#this);
-static method Extension5|method3<T extends core::Object? = core::Object?, S extends dynamic = dynamic>(lowered final self::Extension5|method3::T% #this) → dynamic
+static method Extension5|get#method2<T extends core::Object?>(lowered final self::Extension5|get#method2::T% #this) → <S extends core::String>() → dynamic
+  return <S extends core::String>() → dynamic => self::Extension5|method2<self::Extension5|get#method2::T%, S>(#this);
+static method Extension5|method3<T extends core::Object?, S extends dynamic>(lowered final self::Extension5|method3::T% #this) → dynamic
   ;
-static method Extension5|get#method3<T extends core::Object? = core::Object?>(lowered final self::Extension5|get#method3::T% #this) → <S extends dynamic = dynamic>() → dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension5|method3<self::Extension5|get#method3::T%, S%>(#this);
-static method Extension5|method4<T extends core::Object? = core::Object?, S extends core::Object? = dynamic>(lowered final self::Extension5|method4::T% #this) → dynamic
+static method Extension5|get#method3<T extends core::Object?>(lowered final self::Extension5|get#method3::T% #this) → <S extends dynamic>() → dynamic
+  return <S extends dynamic>() → dynamic => self::Extension5|method3<self::Extension5|get#method3::T%, S%>(#this);
+static method Extension5|method4<T extends core::Object?, S extends core::Object? = dynamic>(lowered final self::Extension5|method4::T% #this) → dynamic
   ;
-static method Extension5|get#method4<T extends core::Object? = core::Object?>(lowered final self::Extension5|get#method4::T% #this) → <S extends core::Object? = dynamic>() → dynamic
+static method Extension5|get#method4<T extends core::Object?>(lowered final self::Extension5|get#method4::T% #this) → <S extends core::Object? = dynamic>() → dynamic
   return <S extends core::Object? = dynamic>() → dynamic => self::Extension5|method4<self::Extension5|get#method4::T%, S%>(#this);
-static method Extension5|method5<T extends core::Object? = core::Object?, S extends core::Object? = core::Object?>(lowered final self::Extension5|method5::T% #this) → dynamic
+static method Extension5|method5<T extends core::Object?, S extends core::Object?>(lowered final self::Extension5|method5::T% #this) → dynamic
   ;
-static method Extension5|get#method5<T extends core::Object? = core::Object?>(lowered final self::Extension5|get#method5::T% #this) → <S extends core::Object? = core::Object?>() → dynamic
-  return <S extends core::Object? = core::Object?>() → dynamic => self::Extension5|method5<self::Extension5|get#method5::T%, S%>(#this);
+static method Extension5|get#method5<T extends core::Object?>(lowered final self::Extension5|get#method5::T% #this) → <S extends core::Object?>() → dynamic
+  return <S extends core::Object?>() → dynamic => self::Extension5|method5<self::Extension5|get#method5::T%, S%>(#this);
 static method main() → dynamic
   ;
diff --git a/pkg/front_end/testcases/nnbd/extension_bounds.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/extension_bounds.dart.weak.transformed.expect
index c1de6b4..71679c9 100644
--- a/pkg/front_end/testcases/nnbd/extension_bounds.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/extension_bounds.dart.weak.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-extension Extension1<T extends core::Object = core::Object> on T {
+extension Extension1<T extends core::Object> on T {
   method method1 = self::Extension1|method1;
   tearoff method1 = self::Extension1|get#method1;
   method method2 = self::Extension1|method2;
@@ -14,7 +14,7 @@
   method method5 = self::Extension1|method5;
   tearoff method5 = self::Extension1|get#method5;
 }
-extension Extension2<T extends core::String = core::String> on T {
+extension Extension2<T extends core::String> on T {
   method method1 = self::Extension2|method1;
   tearoff method1 = self::Extension2|get#method1;
   method method2 = self::Extension2|method2;
@@ -26,7 +26,7 @@
   method method5 = self::Extension2|method5;
   tearoff method5 = self::Extension2|get#method5;
 }
-extension Extension3<T extends dynamic = dynamic> on T% {
+extension Extension3<T extends dynamic> on T% {
   method method1 = self::Extension3|method1;
   tearoff method1 = self::Extension3|get#method1;
   method method2 = self::Extension3|method2;
@@ -50,7 +50,7 @@
   method method5 = self::Extension4|method5;
   tearoff method5 = self::Extension4|get#method5;
 }
-extension Extension5<T extends core::Object? = core::Object?> on T% {
+extension Extension5<T extends core::Object?> on T% {
   method method1 = self::Extension5|method1;
   tearoff method1 = self::Extension5|get#method1;
   method method2 = self::Extension5|method2;
@@ -62,79 +62,79 @@
   method method5 = self::Extension5|method5;
   tearoff method5 = self::Extension5|get#method5;
 }
-static method Extension1|method1<T extends core::Object = core::Object, S extends core::Object = core::Object>(lowered final self::Extension1|method1::T #this) → dynamic {}
-static method Extension1|get#method1<T extends core::Object = core::Object>(lowered final self::Extension1|get#method1::T #this) → <S extends core::Object = core::Object>() → dynamic
-  return <S extends core::Object = core::Object>() → dynamic => self::Extension1|method1<self::Extension1|get#method1::T, S>(#this);
-static method Extension1|method2<T extends core::Object = core::Object, S extends core::String = core::String>(lowered final self::Extension1|method2::T #this) → dynamic {}
-static method Extension1|get#method2<T extends core::Object = core::Object>(lowered final self::Extension1|get#method2::T #this) → <S extends core::String = core::String>() → dynamic
-  return <S extends core::String = core::String>() → dynamic => self::Extension1|method2<self::Extension1|get#method2::T, S>(#this);
-static method Extension1|method3<T extends core::Object = core::Object, S extends dynamic = dynamic>(lowered final self::Extension1|method3::T #this) → dynamic {}
-static method Extension1|get#method3<T extends core::Object = core::Object>(lowered final self::Extension1|get#method3::T #this) → <S extends dynamic = dynamic>() → dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension1|method3<self::Extension1|get#method3::T, S%>(#this);
-static method Extension1|method4<T extends core::Object = core::Object, S extends core::Object? = dynamic>(lowered final self::Extension1|method4::T #this) → dynamic {}
-static method Extension1|get#method4<T extends core::Object = core::Object>(lowered final self::Extension1|get#method4::T #this) → <S extends core::Object? = dynamic>() → dynamic
+static method Extension1|method1<T extends core::Object, S extends core::Object>(lowered final self::Extension1|method1::T #this) → dynamic {}
+static method Extension1|get#method1<T extends core::Object>(lowered final self::Extension1|get#method1::T #this) → <S extends core::Object>() → dynamic
+  return <S extends core::Object>() → dynamic => self::Extension1|method1<self::Extension1|get#method1::T, S>(#this);
+static method Extension1|method2<T extends core::Object, S extends core::String>(lowered final self::Extension1|method2::T #this) → dynamic {}
+static method Extension1|get#method2<T extends core::Object>(lowered final self::Extension1|get#method2::T #this) → <S extends core::String>() → dynamic
+  return <S extends core::String>() → dynamic => self::Extension1|method2<self::Extension1|get#method2::T, S>(#this);
+static method Extension1|method3<T extends core::Object, S extends dynamic>(lowered final self::Extension1|method3::T #this) → dynamic {}
+static method Extension1|get#method3<T extends core::Object>(lowered final self::Extension1|get#method3::T #this) → <S extends dynamic>() → dynamic
+  return <S extends dynamic>() → dynamic => self::Extension1|method3<self::Extension1|get#method3::T, S%>(#this);
+static method Extension1|method4<T extends core::Object, S extends core::Object? = dynamic>(lowered final self::Extension1|method4::T #this) → dynamic {}
+static method Extension1|get#method4<T extends core::Object>(lowered final self::Extension1|get#method4::T #this) → <S extends core::Object? = dynamic>() → dynamic
   return <S extends core::Object? = dynamic>() → dynamic => self::Extension1|method4<self::Extension1|get#method4::T, S%>(#this);
-static method Extension1|method5<T extends core::Object = core::Object, S extends core::Object? = core::Object?>(lowered final self::Extension1|method5::T #this) → dynamic {}
-static method Extension1|get#method5<T extends core::Object = core::Object>(lowered final self::Extension1|get#method5::T #this) → <S extends core::Object? = core::Object?>() → dynamic
-  return <S extends core::Object? = core::Object?>() → dynamic => self::Extension1|method5<self::Extension1|get#method5::T, S%>(#this);
-static method Extension2|method1<T extends core::String = core::String, S extends core::Object = core::Object>(lowered final self::Extension2|method1::T #this) → dynamic {}
-static method Extension2|get#method1<T extends core::String = core::String>(lowered final self::Extension2|get#method1::T #this) → <S extends core::Object = core::Object>() → dynamic
-  return <S extends core::Object = core::Object>() → dynamic => self::Extension2|method1<self::Extension2|get#method1::T, S>(#this);
-static method Extension2|method2<T extends core::String = core::String, S extends core::String = core::String>(lowered final self::Extension2|method2::T #this) → dynamic {}
-static method Extension2|get#method2<T extends core::String = core::String>(lowered final self::Extension2|get#method2::T #this) → <S extends core::String = core::String>() → dynamic
-  return <S extends core::String = core::String>() → dynamic => self::Extension2|method2<self::Extension2|get#method2::T, S>(#this);
-static method Extension2|method3<T extends core::String = core::String, S extends dynamic = dynamic>(lowered final self::Extension2|method3::T #this) → dynamic {}
-static method Extension2|get#method3<T extends core::String = core::String>(lowered final self::Extension2|get#method3::T #this) → <S extends dynamic = dynamic>() → dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension2|method3<self::Extension2|get#method3::T, S%>(#this);
-static method Extension2|get#method4<T extends core::String = core::String>(lowered final self::Extension2|get#method4::T #this) → <S extends core::Object? = dynamic>() → dynamic
+static method Extension1|method5<T extends core::Object, S extends core::Object?>(lowered final self::Extension1|method5::T #this) → dynamic {}
+static method Extension1|get#method5<T extends core::Object>(lowered final self::Extension1|get#method5::T #this) → <S extends core::Object?>() → dynamic
+  return <S extends core::Object?>() → dynamic => self::Extension1|method5<self::Extension1|get#method5::T, S%>(#this);
+static method Extension2|method1<T extends core::String, S extends core::Object>(lowered final self::Extension2|method1::T #this) → dynamic {}
+static method Extension2|get#method1<T extends core::String>(lowered final self::Extension2|get#method1::T #this) → <S extends core::Object>() → dynamic
+  return <S extends core::Object>() → dynamic => self::Extension2|method1<self::Extension2|get#method1::T, S>(#this);
+static method Extension2|method2<T extends core::String, S extends core::String>(lowered final self::Extension2|method2::T #this) → dynamic {}
+static method Extension2|get#method2<T extends core::String>(lowered final self::Extension2|get#method2::T #this) → <S extends core::String>() → dynamic
+  return <S extends core::String>() → dynamic => self::Extension2|method2<self::Extension2|get#method2::T, S>(#this);
+static method Extension2|method3<T extends core::String, S extends dynamic>(lowered final self::Extension2|method3::T #this) → dynamic {}
+static method Extension2|get#method3<T extends core::String>(lowered final self::Extension2|get#method3::T #this) → <S extends dynamic>() → dynamic
+  return <S extends dynamic>() → dynamic => self::Extension2|method3<self::Extension2|get#method3::T, S%>(#this);
+static method Extension2|get#method4<T extends core::String>(lowered final self::Extension2|get#method4::T #this) → <S extends core::Object? = dynamic>() → dynamic
   return <S extends core::Object? = dynamic>() → dynamic => self::Extension2|method4<self::Extension2|get#method4::T, S%>(#this);
-static method Extension2|method4<T extends core::String = core::String, S extends core::Object? = dynamic>(lowered final self::Extension2|method4::T #this) → dynamic {}
-static method Extension2|method5<T extends core::String = core::String, S extends core::Object? = core::Object?>(lowered final self::Extension2|method5::T #this) → dynamic {}
-static method Extension2|get#method5<T extends core::String = core::String>(lowered final self::Extension2|get#method5::T #this) → <S extends core::Object? = core::Object?>() → dynamic
-  return <S extends core::Object? = core::Object?>() → dynamic => self::Extension2|method5<self::Extension2|get#method5::T, S%>(#this);
-static method Extension3|method1<T extends dynamic = dynamic, S extends core::Object = core::Object>(lowered final self::Extension3|method1::T% #this) → dynamic {}
-static method Extension3|get#method1<T extends dynamic = dynamic>(lowered final self::Extension3|get#method1::T% #this) → <S extends core::Object = core::Object>() → dynamic
-  return <S extends core::Object = core::Object>() → dynamic => self::Extension3|method1<self::Extension3|get#method1::T%, S>(#this);
-static method Extension3|method2<T extends dynamic = dynamic, S extends core::String = core::String>(lowered final self::Extension3|method2::T% #this) → dynamic {}
-static method Extension3|get#method2<T extends dynamic = dynamic>(lowered final self::Extension3|get#method2::T% #this) → <S extends core::String = core::String>() → dynamic
-  return <S extends core::String = core::String>() → dynamic => self::Extension3|method2<self::Extension3|get#method2::T%, S>(#this);
-static method Extension3|method3<T extends dynamic = dynamic, S extends dynamic = dynamic>(lowered final self::Extension3|method3::T% #this) → dynamic {}
-static method Extension3|get#method3<T extends dynamic = dynamic>(lowered final self::Extension3|get#method3::T% #this) → <S extends dynamic = dynamic>() → dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension3|method3<self::Extension3|get#method3::T%, S%>(#this);
-static method Extension3|method4<T extends dynamic = dynamic, S extends core::Object? = dynamic>(lowered final self::Extension3|method4::T% #this) → dynamic {}
-static method Extension3|get#method4<T extends dynamic = dynamic>(lowered final self::Extension3|get#method4::T% #this) → <S extends core::Object? = dynamic>() → dynamic
+static method Extension2|method4<T extends core::String, S extends core::Object? = dynamic>(lowered final self::Extension2|method4::T #this) → dynamic {}
+static method Extension2|method5<T extends core::String, S extends core::Object?>(lowered final self::Extension2|method5::T #this) → dynamic {}
+static method Extension2|get#method5<T extends core::String>(lowered final self::Extension2|get#method5::T #this) → <S extends core::Object?>() → dynamic
+  return <S extends core::Object?>() → dynamic => self::Extension2|method5<self::Extension2|get#method5::T, S%>(#this);
+static method Extension3|method1<T extends dynamic, S extends core::Object>(lowered final self::Extension3|method1::T% #this) → dynamic {}
+static method Extension3|get#method1<T extends dynamic>(lowered final self::Extension3|get#method1::T% #this) → <S extends core::Object>() → dynamic
+  return <S extends core::Object>() → dynamic => self::Extension3|method1<self::Extension3|get#method1::T%, S>(#this);
+static method Extension3|method2<T extends dynamic, S extends core::String>(lowered final self::Extension3|method2::T% #this) → dynamic {}
+static method Extension3|get#method2<T extends dynamic>(lowered final self::Extension3|get#method2::T% #this) → <S extends core::String>() → dynamic
+  return <S extends core::String>() → dynamic => self::Extension3|method2<self::Extension3|get#method2::T%, S>(#this);
+static method Extension3|method3<T extends dynamic, S extends dynamic>(lowered final self::Extension3|method3::T% #this) → dynamic {}
+static method Extension3|get#method3<T extends dynamic>(lowered final self::Extension3|get#method3::T% #this) → <S extends dynamic>() → dynamic
+  return <S extends dynamic>() → dynamic => self::Extension3|method3<self::Extension3|get#method3::T%, S%>(#this);
+static method Extension3|method4<T extends dynamic, S extends core::Object? = dynamic>(lowered final self::Extension3|method4::T% #this) → dynamic {}
+static method Extension3|get#method4<T extends dynamic>(lowered final self::Extension3|get#method4::T% #this) → <S extends core::Object? = dynamic>() → dynamic
   return <S extends core::Object? = dynamic>() → dynamic => self::Extension3|method4<self::Extension3|get#method4::T%, S%>(#this);
-static method Extension3|method5<T extends dynamic = dynamic, S extends core::Object? = core::Object?>(lowered final self::Extension3|method5::T% #this) → dynamic {}
-static method Extension3|get#method5<T extends dynamic = dynamic>(lowered final self::Extension3|get#method5::T% #this) → <S extends core::Object? = core::Object?>() → dynamic
-  return <S extends core::Object? = core::Object?>() → dynamic => self::Extension3|method5<self::Extension3|get#method5::T%, S%>(#this);
-static method Extension4|method1<T extends core::Object? = dynamic, S extends core::Object = core::Object>(lowered final self::Extension4|method1::T% #this) → dynamic {}
-static method Extension4|get#method1<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method1::T% #this) → <S extends core::Object = core::Object>() → dynamic
-  return <S extends core::Object = core::Object>() → dynamic => self::Extension4|method1<self::Extension4|get#method1::T%, S>(#this);
-static method Extension4|method2<T extends core::Object? = dynamic, S extends core::String = core::String>(lowered final self::Extension4|method2::T% #this) → dynamic {}
-static method Extension4|get#method2<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method2::T% #this) → <S extends core::String = core::String>() → dynamic
-  return <S extends core::String = core::String>() → dynamic => self::Extension4|method2<self::Extension4|get#method2::T%, S>(#this);
-static method Extension4|method3<T extends core::Object? = dynamic, S extends dynamic = dynamic>(lowered final self::Extension4|method3::T% #this) → dynamic {}
-static method Extension4|get#method3<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method3::T% #this) → <S extends dynamic = dynamic>() → dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension4|method3<self::Extension4|get#method3::T%, S%>(#this);
+static method Extension3|method5<T extends dynamic, S extends core::Object?>(lowered final self::Extension3|method5::T% #this) → dynamic {}
+static method Extension3|get#method5<T extends dynamic>(lowered final self::Extension3|get#method5::T% #this) → <S extends core::Object?>() → dynamic
+  return <S extends core::Object?>() → dynamic => self::Extension3|method5<self::Extension3|get#method5::T%, S%>(#this);
+static method Extension4|method1<T extends core::Object? = dynamic, S extends core::Object>(lowered final self::Extension4|method1::T% #this) → dynamic {}
+static method Extension4|get#method1<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method1::T% #this) → <S extends core::Object>() → dynamic
+  return <S extends core::Object>() → dynamic => self::Extension4|method1<self::Extension4|get#method1::T%, S>(#this);
+static method Extension4|method2<T extends core::Object? = dynamic, S extends core::String>(lowered final self::Extension4|method2::T% #this) → dynamic {}
+static method Extension4|get#method2<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method2::T% #this) → <S extends core::String>() → dynamic
+  return <S extends core::String>() → dynamic => self::Extension4|method2<self::Extension4|get#method2::T%, S>(#this);
+static method Extension4|method3<T extends core::Object? = dynamic, S extends dynamic>(lowered final self::Extension4|method3::T% #this) → dynamic {}
+static method Extension4|get#method3<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method3::T% #this) → <S extends dynamic>() → dynamic
+  return <S extends dynamic>() → dynamic => self::Extension4|method3<self::Extension4|get#method3::T%, S%>(#this);
 static method Extension4|method4<T extends core::Object? = dynamic, S extends core::Object? = dynamic>(lowered final self::Extension4|method4::T% #this) → dynamic {}
 static method Extension4|get#method4<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method4::T% #this) → <S extends core::Object? = dynamic>() → dynamic
   return <S extends core::Object? = dynamic>() → dynamic => self::Extension4|method4<self::Extension4|get#method4::T%, S%>(#this);
-static method Extension4|method5<T extends core::Object? = dynamic, S extends core::Object? = core::Object?>(lowered final self::Extension4|method5::T% #this) → dynamic {}
-static method Extension4|get#method5<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method5::T% #this) → <S extends core::Object? = core::Object?>() → dynamic
-  return <S extends core::Object? = core::Object?>() → dynamic => self::Extension4|method5<self::Extension4|get#method5::T%, S%>(#this);
-static method Extension5|method1<T extends core::Object? = core::Object?, S extends core::Object = core::Object>(lowered final self::Extension5|method1::T% #this) → dynamic {}
-static method Extension5|get#method1<T extends core::Object? = core::Object?>(lowered final self::Extension5|get#method1::T% #this) → <S extends core::Object = core::Object>() → dynamic
-  return <S extends core::Object = core::Object>() → dynamic => self::Extension5|method1<self::Extension5|get#method1::T%, S>(#this);
-static method Extension5|method2<T extends core::Object? = core::Object?, S extends core::String = core::String>(lowered final self::Extension5|method2::T% #this) → dynamic {}
-static method Extension5|get#method2<T extends core::Object? = core::Object?>(lowered final self::Extension5|get#method2::T% #this) → <S extends core::String = core::String>() → dynamic
-  return <S extends core::String = core::String>() → dynamic => self::Extension5|method2<self::Extension5|get#method2::T%, S>(#this);
-static method Extension5|method3<T extends core::Object? = core::Object?, S extends dynamic = dynamic>(lowered final self::Extension5|method3::T% #this) → dynamic {}
-static method Extension5|get#method3<T extends core::Object? = core::Object?>(lowered final self::Extension5|get#method3::T% #this) → <S extends dynamic = dynamic>() → dynamic
-  return <S extends dynamic = dynamic>() → dynamic => self::Extension5|method3<self::Extension5|get#method3::T%, S%>(#this);
-static method Extension5|method4<T extends core::Object? = core::Object?, S extends core::Object? = dynamic>(lowered final self::Extension5|method4::T% #this) → dynamic {}
-static method Extension5|get#method4<T extends core::Object? = core::Object?>(lowered final self::Extension5|get#method4::T% #this) → <S extends core::Object? = dynamic>() → dynamic
+static method Extension4|method5<T extends core::Object? = dynamic, S extends core::Object?>(lowered final self::Extension4|method5::T% #this) → dynamic {}
+static method Extension4|get#method5<T extends core::Object? = dynamic>(lowered final self::Extension4|get#method5::T% #this) → <S extends core::Object?>() → dynamic
+  return <S extends core::Object?>() → dynamic => self::Extension4|method5<self::Extension4|get#method5::T%, S%>(#this);
+static method Extension5|method1<T extends core::Object?, S extends core::Object>(lowered final self::Extension5|method1::T% #this) → dynamic {}
+static method Extension5|get#method1<T extends core::Object?>(lowered final self::Extension5|get#method1::T% #this) → <S extends core::Object>() → dynamic
+  return <S extends core::Object>() → dynamic => self::Extension5|method1<self::Extension5|get#method1::T%, S>(#this);
+static method Extension5|method2<T extends core::Object?, S extends core::String>(lowered final self::Extension5|method2::T% #this) → dynamic {}
+static method Extension5|get#method2<T extends core::Object?>(lowered final self::Extension5|get#method2::T% #this) → <S extends core::String>() → dynamic
+  return <S extends core::String>() → dynamic => self::Extension5|method2<self::Extension5|get#method2::T%, S>(#this);
+static method Extension5|method3<T extends core::Object?, S extends dynamic>(lowered final self::Extension5|method3::T% #this) → dynamic {}
+static method Extension5|get#method3<T extends core::Object?>(lowered final self::Extension5|get#method3::T% #this) → <S extends dynamic>() → dynamic
+  return <S extends dynamic>() → dynamic => self::Extension5|method3<self::Extension5|get#method3::T%, S%>(#this);
+static method Extension5|method4<T extends core::Object?, S extends core::Object? = dynamic>(lowered final self::Extension5|method4::T% #this) → dynamic {}
+static method Extension5|get#method4<T extends core::Object?>(lowered final self::Extension5|get#method4::T% #this) → <S extends core::Object? = dynamic>() → dynamic
   return <S extends core::Object? = dynamic>() → dynamic => self::Extension5|method4<self::Extension5|get#method4::T%, S%>(#this);
-static method Extension5|method5<T extends core::Object? = core::Object?, S extends core::Object? = core::Object?>(lowered final self::Extension5|method5::T% #this) → dynamic {}
-static method Extension5|get#method5<T extends core::Object? = core::Object?>(lowered final self::Extension5|get#method5::T% #this) → <S extends core::Object? = core::Object?>() → dynamic
-  return <S extends core::Object? = core::Object?>() → dynamic => self::Extension5|method5<self::Extension5|get#method5::T%, S%>(#this);
+static method Extension5|method5<T extends core::Object?, S extends core::Object?>(lowered final self::Extension5|method5::T% #this) → dynamic {}
+static method Extension5|get#method5<T extends core::Object?>(lowered final self::Extension5|get#method5::T% #this) → <S extends core::Object?>() → dynamic
+  return <S extends core::Object?>() → dynamic => self::Extension5|method5<self::Extension5|get#method5::T%, S%>(#this);
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd/extension_type_variable_bound.dart.strong.expect b/pkg/front_end/testcases/nnbd/extension_type_variable_bound.dart.strong.expect
index b4f5d7a..9eabe2c 100644
--- a/pkg/front_end/testcases/nnbd/extension_type_variable_bound.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/extension_type_variable_bound.dart.strong.expect
@@ -35,7 +35,7 @@
   method method1 = self::Extension|method1;
   tearoff method1 = self::Extension|get#method1;
 }
-extension BoundExtension<T extends self::Class = self::Class> on T {
+extension BoundExtension<T extends self::Class> on T {
   method method2 = self::BoundExtension|method2;
   tearoff method2 = self::BoundExtension|get#method2;
 }
@@ -43,9 +43,9 @@
   return #this;
 static method Extension|get#method1<T extends core::Object? = dynamic>(lowered final self::Extension|get#method1::T% #this) → () → self::Extension|get#method1::T%
   return () → self::Extension|get#method1::T% => self::Extension|method1<self::Extension|get#method1::T%>(#this);
-static method BoundExtension|method2<T extends self::Class = self::Class>(lowered final self::BoundExtension|method2::T #this) → self::BoundExtension|method2::T
+static method BoundExtension|method2<T extends self::Class>(lowered final self::BoundExtension|method2::T #this) → self::BoundExtension|method2::T
   return #this;
-static method BoundExtension|get#method2<T extends self::Class = self::Class>(lowered final self::BoundExtension|get#method2::T #this) → () → self::BoundExtension|get#method2::T
+static method BoundExtension|get#method2<T extends self::Class>(lowered final self::BoundExtension|get#method2::T #this) → () → self::BoundExtension|get#method2::T
   return () → self::BoundExtension|get#method2::T => self::BoundExtension|method2<self::BoundExtension|get#method2::T>(#this);
 static method test1<T extends core::Object? = dynamic>(self::test1::T% t1) → self::Class {
   if(t1 is{ForNonNullableByDefault} self::SubClass) {
@@ -56,7 +56,7 @@
   }
   return new self::Class::•();
 }
-static method test2<T extends self::Class = self::Class>(self::test2::T t2) → dynamic {
+static method test2<T extends self::Class>(self::test2::T t2) → dynamic {
   if(self::test2::T.{core::Type::==}(#C1)) {
     self::SubClass subClass = let final Never #t2 = invalid-expression "pkg/front_end/testcases/nnbd/extension_type_variable_bound.dart:26:28: Error: A value of type 'T' can't be assigned to a variable of type 'SubClass'.
  - 'SubClass' is from 'pkg/front_end/testcases/nnbd/extension_type_variable_bound.dart'.
diff --git a/pkg/front_end/testcases/nnbd/extension_type_variable_bound.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/extension_type_variable_bound.dart.strong.transformed.expect
index 19b39bd..3d46c4f 100644
--- a/pkg/front_end/testcases/nnbd/extension_type_variable_bound.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/extension_type_variable_bound.dart.strong.transformed.expect
@@ -35,7 +35,7 @@
   method method1 = self::Extension|method1;
   tearoff method1 = self::Extension|get#method1;
 }
-extension BoundExtension<T extends self::Class = self::Class> on T {
+extension BoundExtension<T extends self::Class> on T {
   method method2 = self::BoundExtension|method2;
   tearoff method2 = self::BoundExtension|get#method2;
 }
@@ -43,9 +43,9 @@
   return #this;
 static method Extension|get#method1<T extends core::Object? = dynamic>(lowered final self::Extension|get#method1::T% #this) → () → self::Extension|get#method1::T%
   return () → self::Extension|get#method1::T% => self::Extension|method1<self::Extension|get#method1::T%>(#this);
-static method BoundExtension|method2<T extends self::Class = self::Class>(lowered final self::BoundExtension|method2::T #this) → self::BoundExtension|method2::T
+static method BoundExtension|method2<T extends self::Class>(lowered final self::BoundExtension|method2::T #this) → self::BoundExtension|method2::T
   return #this;
-static method BoundExtension|get#method2<T extends self::Class = self::Class>(lowered final self::BoundExtension|get#method2::T #this) → () → self::BoundExtension|get#method2::T
+static method BoundExtension|get#method2<T extends self::Class>(lowered final self::BoundExtension|get#method2::T #this) → () → self::BoundExtension|get#method2::T
   return () → self::BoundExtension|get#method2::T => self::BoundExtension|method2<self::BoundExtension|get#method2::T>(#this);
 static method test1<T extends core::Object? = dynamic>(self::test1::T% t1) → self::Class {
   if(t1 is{ForNonNullableByDefault} self::SubClass) {
@@ -56,7 +56,7 @@
   }
   return new self::Class::•();
 }
-static method test2<T extends self::Class = self::Class>(self::test2::T t2) → dynamic {
+static method test2<T extends self::Class>(self::test2::T t2) → dynamic {
   if(self::test2::T.{core::Type::==}(#C1)) {
     self::SubClass subClass = let final Never #t2 = invalid-expression "pkg/front_end/testcases/nnbd/extension_type_variable_bound.dart:26:28: Error: A value of type 'T' can't be assigned to a variable of type 'SubClass'.
  - 'SubClass' is from 'pkg/front_end/testcases/nnbd/extension_type_variable_bound.dart'.
diff --git a/pkg/front_end/testcases/nnbd/extension_type_variable_bound.dart.weak.expect b/pkg/front_end/testcases/nnbd/extension_type_variable_bound.dart.weak.expect
index 826d688..b1bfc74 100644
--- a/pkg/front_end/testcases/nnbd/extension_type_variable_bound.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/extension_type_variable_bound.dart.weak.expect
@@ -35,7 +35,7 @@
   method method1 = self::Extension|method1;
   tearoff method1 = self::Extension|get#method1;
 }
-extension BoundExtension<T extends self::Class = self::Class> on T {
+extension BoundExtension<T extends self::Class> on T {
   method method2 = self::BoundExtension|method2;
   tearoff method2 = self::BoundExtension|get#method2;
 }
@@ -43,9 +43,9 @@
   return #this;
 static method Extension|get#method1<T extends core::Object? = dynamic>(lowered final self::Extension|get#method1::T% #this) → () → self::Extension|get#method1::T%
   return () → self::Extension|get#method1::T% => self::Extension|method1<self::Extension|get#method1::T%>(#this);
-static method BoundExtension|method2<T extends self::Class = self::Class>(lowered final self::BoundExtension|method2::T #this) → self::BoundExtension|method2::T
+static method BoundExtension|method2<T extends self::Class>(lowered final self::BoundExtension|method2::T #this) → self::BoundExtension|method2::T
   return #this;
-static method BoundExtension|get#method2<T extends self::Class = self::Class>(lowered final self::BoundExtension|get#method2::T #this) → () → self::BoundExtension|get#method2::T
+static method BoundExtension|get#method2<T extends self::Class>(lowered final self::BoundExtension|get#method2::T #this) → () → self::BoundExtension|get#method2::T
   return () → self::BoundExtension|get#method2::T => self::BoundExtension|method2<self::BoundExtension|get#method2::T>(#this);
 static method test1<T extends core::Object? = dynamic>(self::test1::T% t1) → self::Class {
   if(t1 is{ForNonNullableByDefault} self::SubClass) {
@@ -56,7 +56,7 @@
   }
   return new self::Class::•();
 }
-static method test2<T extends self::Class = self::Class>(self::test2::T t2) → dynamic {
+static method test2<T extends self::Class>(self::test2::T t2) → dynamic {
   if(self::test2::T.{core::Type::==}(#C1)) {
     self::SubClass subClass = let final Never #t2 = invalid-expression "pkg/front_end/testcases/nnbd/extension_type_variable_bound.dart:26:28: Error: A value of type 'T' can't be assigned to a variable of type 'SubClass'.
  - 'SubClass' is from 'pkg/front_end/testcases/nnbd/extension_type_variable_bound.dart'.
diff --git a/pkg/front_end/testcases/nnbd/extension_type_variable_bound.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/extension_type_variable_bound.dart.weak.outline.expect
index 7798a93..1a7ba19 100644
--- a/pkg/front_end/testcases/nnbd/extension_type_variable_bound.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/extension_type_variable_bound.dart.weak.outline.expect
@@ -14,7 +14,7 @@
   method method1 = self::Extension|method1;
   tearoff method1 = self::Extension|get#method1;
 }
-extension BoundExtension<T extends self::Class = self::Class> on T {
+extension BoundExtension<T extends self::Class> on T {
   method method2 = self::BoundExtension|method2;
   tearoff method2 = self::BoundExtension|get#method2;
 }
@@ -22,13 +22,13 @@
   ;
 static method Extension|get#method1<T extends core::Object? = dynamic>(lowered final self::Extension|get#method1::T% #this) → () → self::Extension|get#method1::T%
   return () → self::Extension|get#method1::T% => self::Extension|method1<self::Extension|get#method1::T%>(#this);
-static method BoundExtension|method2<T extends self::Class = self::Class>(lowered final self::BoundExtension|method2::T #this) → self::BoundExtension|method2::T
+static method BoundExtension|method2<T extends self::Class>(lowered final self::BoundExtension|method2::T #this) → self::BoundExtension|method2::T
   ;
-static method BoundExtension|get#method2<T extends self::Class = self::Class>(lowered final self::BoundExtension|get#method2::T #this) → () → self::BoundExtension|get#method2::T
+static method BoundExtension|get#method2<T extends self::Class>(lowered final self::BoundExtension|get#method2::T #this) → () → self::BoundExtension|get#method2::T
   return () → self::BoundExtension|get#method2::T => self::BoundExtension|method2<self::BoundExtension|get#method2::T>(#this);
 static method test1<T extends core::Object? = dynamic>(self::test1::T% t1) → self::Class
   ;
-static method test2<T extends self::Class = self::Class>(self::test2::T t2) → dynamic
+static method test2<T extends self::Class>(self::test2::T t2) → dynamic
   ;
 static method test3<T extends core::Object? = dynamic>(self::test3::T% t3) → dynamic
   ;
diff --git a/pkg/front_end/testcases/nnbd/extension_type_variable_bound.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/extension_type_variable_bound.dart.weak.transformed.expect
index fb35bc5..ae9d534 100644
--- a/pkg/front_end/testcases/nnbd/extension_type_variable_bound.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/extension_type_variable_bound.dart.weak.transformed.expect
@@ -35,7 +35,7 @@
   method method1 = self::Extension|method1;
   tearoff method1 = self::Extension|get#method1;
 }
-extension BoundExtension<T extends self::Class = self::Class> on T {
+extension BoundExtension<T extends self::Class> on T {
   method method2 = self::BoundExtension|method2;
   tearoff method2 = self::BoundExtension|get#method2;
 }
@@ -43,9 +43,9 @@
   return #this;
 static method Extension|get#method1<T extends core::Object? = dynamic>(lowered final self::Extension|get#method1::T% #this) → () → self::Extension|get#method1::T%
   return () → self::Extension|get#method1::T% => self::Extension|method1<self::Extension|get#method1::T%>(#this);
-static method BoundExtension|method2<T extends self::Class = self::Class>(lowered final self::BoundExtension|method2::T #this) → self::BoundExtension|method2::T
+static method BoundExtension|method2<T extends self::Class>(lowered final self::BoundExtension|method2::T #this) → self::BoundExtension|method2::T
   return #this;
-static method BoundExtension|get#method2<T extends self::Class = self::Class>(lowered final self::BoundExtension|get#method2::T #this) → () → self::BoundExtension|get#method2::T
+static method BoundExtension|get#method2<T extends self::Class>(lowered final self::BoundExtension|get#method2::T #this) → () → self::BoundExtension|get#method2::T
   return () → self::BoundExtension|get#method2::T => self::BoundExtension|method2<self::BoundExtension|get#method2::T>(#this);
 static method test1<T extends core::Object? = dynamic>(self::test1::T% t1) → self::Class {
   if(t1 is{ForNonNullableByDefault} self::SubClass) {
@@ -56,7 +56,7 @@
   }
   return new self::Class::•();
 }
-static method test2<T extends self::Class = self::Class>(self::test2::T t2) → dynamic {
+static method test2<T extends self::Class>(self::test2::T t2) → dynamic {
   if(self::test2::T.{core::Type::==}(#C1)) {
     self::SubClass subClass = let final Never #t2 = invalid-expression "pkg/front_end/testcases/nnbd/extension_type_variable_bound.dart:26:28: Error: A value of type 'T' can't be assigned to a variable of type 'SubClass'.
  - 'SubClass' is from 'pkg/front_end/testcases/nnbd/extension_type_variable_bound.dart'.
diff --git a/pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart.strong.expect b/pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart.strong.expect
index 70b4d24..37f68ac 100644
--- a/pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart.strong.expect
@@ -212,7 +212,7 @@
     : super core::Object::•()
     ;
 }
-extension Extension<T extends core::num = core::num> on core::int {
+extension Extension<T extends core::num> on core::int {
   get property1 = self::Extension|get#property1;
   get property2 = self::Extension|get#property2;
   get property3 = self::Extension|get#property3;
@@ -243,35 +243,35 @@
 static get property3() → core::int?
   return 0;
 static set property3(core::int value) → void {}
-static method Extension|get#property1<T extends core::num = core::num>(lowered final core::int #this) → core::int
+static method Extension|get#property1<T extends core::num>(lowered final core::int #this) → core::int
   return 0;
-static method Extension|set#property1<T extends core::num = core::num>(lowered final core::int #this, core::int i) → void {}
-static method Extension|get#property2<T extends core::num = core::num>(lowered final core::int #this) → core::int
+static method Extension|set#property1<T extends core::num>(lowered final core::int #this, core::int i) → void {}
+static method Extension|get#property2<T extends core::num>(lowered final core::int #this) → core::int
   return 0;
-static method Extension|set#property2<T extends core::num = core::num>(lowered final core::int #this, core::int? i) → void {}
-static method Extension|get#property3<T extends core::num = core::num>(lowered final core::int #this) → core::int?
+static method Extension|set#property2<T extends core::num>(lowered final core::int #this, core::int? i) → void {}
+static method Extension|get#property3<T extends core::num>(lowered final core::int #this) → core::int?
   return 0;
-static method Extension|set#property3<T extends core::num = core::num>(lowered final core::int #this, core::int i) → void {}
-static method Extension|get#property4a<T extends core::num = core::num>(lowered final core::int #this) → self::Extension|get#property4a::T
+static method Extension|set#property3<T extends core::num>(lowered final core::int #this, core::int i) → void {}
+static method Extension|get#property4a<T extends core::num>(lowered final core::int #this) → self::Extension|get#property4a::T
   return let final Never #t1 = invalid-expression "pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart:134:23: Error: A value of type 'int' can't be returned from a function with return type 'T'.
   T get property4a => 0; // ok
                       ^" in 0 as{TypeError,ForNonNullableByDefault} Never;
-static method Extension|set#property4a<T extends core::num = core::num>(lowered final core::int #this, self::Extension|set#property4a::T i) → void {}
-static method Extension|get#property4b<T extends core::num = core::num>(lowered final core::int #this) → self::Extension|get#property4b::T?
+static method Extension|set#property4a<T extends core::num>(lowered final core::int #this, self::Extension|set#property4a::T i) → void {}
+static method Extension|get#property4b<T extends core::num>(lowered final core::int #this) → self::Extension|get#property4b::T?
   return let final Never #t2 = invalid-expression "pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart:137:24: Error: A value of type 'int' can't be returned from a function with return type 'T?'.
   T? get property4b => 0; // ok
                        ^" in 0 as{TypeError,ForNonNullableByDefault} Never;
-static method Extension|set#property4b<T extends core::num = core::num>(lowered final core::int #this, self::Extension|set#property4b::T? i) → void {}
-static method Extension|get#property5<T extends core::num = core::num>(lowered final core::int #this) → self::Extension|get#property5::T
+static method Extension|set#property4b<T extends core::num>(lowered final core::int #this, self::Extension|set#property4b::T? i) → void {}
+static method Extension|get#property5<T extends core::num>(lowered final core::int #this) → self::Extension|get#property5::T
   return let final Never #t3 = invalid-expression "pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart:140:22: Error: A value of type 'int' can't be returned from a function with return type 'T'.
   T get property5 => 0; // ok
                      ^" in 0 as{TypeError,ForNonNullableByDefault} Never;
-static method Extension|set#property5<T extends core::num = core::num>(lowered final core::int #this, self::Extension|set#property5::T? i) → void {}
-static method Extension|get#property6<T extends core::num = core::num>(lowered final core::int #this) → self::Extension|get#property6::T?
+static method Extension|set#property5<T extends core::num>(lowered final core::int #this, self::Extension|set#property5::T? i) → void {}
+static method Extension|get#property6<T extends core::num>(lowered final core::int #this) → self::Extension|get#property6::T?
   return let final Never #t4 = invalid-expression "pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart:143:23: Error: A value of type 'int' can't be returned from a function with return type 'T?'.
   T? get property6 => 0; // error
                       ^" in 0 as{TypeError,ForNonNullableByDefault} Never;
-static method Extension|set#property6<T extends core::num = core::num>(lowered final core::int #this, self::Extension|set#property6::T i) → void {}
+static method Extension|set#property6<T extends core::num>(lowered final core::int #this, self::Extension|set#property6::T i) → void {}
 static get Extension|property7() → core::int
   return 0;
 static set Extension|property7(core::int value) → void {}
diff --git a/pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart.strong.transformed.expect
index 70b4d24..37f68ac 100644
--- a/pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart.strong.transformed.expect
@@ -212,7 +212,7 @@
     : super core::Object::•()
     ;
 }
-extension Extension<T extends core::num = core::num> on core::int {
+extension Extension<T extends core::num> on core::int {
   get property1 = self::Extension|get#property1;
   get property2 = self::Extension|get#property2;
   get property3 = self::Extension|get#property3;
@@ -243,35 +243,35 @@
 static get property3() → core::int?
   return 0;
 static set property3(core::int value) → void {}
-static method Extension|get#property1<T extends core::num = core::num>(lowered final core::int #this) → core::int
+static method Extension|get#property1<T extends core::num>(lowered final core::int #this) → core::int
   return 0;
-static method Extension|set#property1<T extends core::num = core::num>(lowered final core::int #this, core::int i) → void {}
-static method Extension|get#property2<T extends core::num = core::num>(lowered final core::int #this) → core::int
+static method Extension|set#property1<T extends core::num>(lowered final core::int #this, core::int i) → void {}
+static method Extension|get#property2<T extends core::num>(lowered final core::int #this) → core::int
   return 0;
-static method Extension|set#property2<T extends core::num = core::num>(lowered final core::int #this, core::int? i) → void {}
-static method Extension|get#property3<T extends core::num = core::num>(lowered final core::int #this) → core::int?
+static method Extension|set#property2<T extends core::num>(lowered final core::int #this, core::int? i) → void {}
+static method Extension|get#property3<T extends core::num>(lowered final core::int #this) → core::int?
   return 0;
-static method Extension|set#property3<T extends core::num = core::num>(lowered final core::int #this, core::int i) → void {}
-static method Extension|get#property4a<T extends core::num = core::num>(lowered final core::int #this) → self::Extension|get#property4a::T
+static method Extension|set#property3<T extends core::num>(lowered final core::int #this, core::int i) → void {}
+static method Extension|get#property4a<T extends core::num>(lowered final core::int #this) → self::Extension|get#property4a::T
   return let final Never #t1 = invalid-expression "pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart:134:23: Error: A value of type 'int' can't be returned from a function with return type 'T'.
   T get property4a => 0; // ok
                       ^" in 0 as{TypeError,ForNonNullableByDefault} Never;
-static method Extension|set#property4a<T extends core::num = core::num>(lowered final core::int #this, self::Extension|set#property4a::T i) → void {}
-static method Extension|get#property4b<T extends core::num = core::num>(lowered final core::int #this) → self::Extension|get#property4b::T?
+static method Extension|set#property4a<T extends core::num>(lowered final core::int #this, self::Extension|set#property4a::T i) → void {}
+static method Extension|get#property4b<T extends core::num>(lowered final core::int #this) → self::Extension|get#property4b::T?
   return let final Never #t2 = invalid-expression "pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart:137:24: Error: A value of type 'int' can't be returned from a function with return type 'T?'.
   T? get property4b => 0; // ok
                        ^" in 0 as{TypeError,ForNonNullableByDefault} Never;
-static method Extension|set#property4b<T extends core::num = core::num>(lowered final core::int #this, self::Extension|set#property4b::T? i) → void {}
-static method Extension|get#property5<T extends core::num = core::num>(lowered final core::int #this) → self::Extension|get#property5::T
+static method Extension|set#property4b<T extends core::num>(lowered final core::int #this, self::Extension|set#property4b::T? i) → void {}
+static method Extension|get#property5<T extends core::num>(lowered final core::int #this) → self::Extension|get#property5::T
   return let final Never #t3 = invalid-expression "pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart:140:22: Error: A value of type 'int' can't be returned from a function with return type 'T'.
   T get property5 => 0; // ok
                      ^" in 0 as{TypeError,ForNonNullableByDefault} Never;
-static method Extension|set#property5<T extends core::num = core::num>(lowered final core::int #this, self::Extension|set#property5::T? i) → void {}
-static method Extension|get#property6<T extends core::num = core::num>(lowered final core::int #this) → self::Extension|get#property6::T?
+static method Extension|set#property5<T extends core::num>(lowered final core::int #this, self::Extension|set#property5::T? i) → void {}
+static method Extension|get#property6<T extends core::num>(lowered final core::int #this) → self::Extension|get#property6::T?
   return let final Never #t4 = invalid-expression "pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart:143:23: Error: A value of type 'int' can't be returned from a function with return type 'T?'.
   T? get property6 => 0; // error
                       ^" in 0 as{TypeError,ForNonNullableByDefault} Never;
-static method Extension|set#property6<T extends core::num = core::num>(lowered final core::int #this, self::Extension|set#property6::T i) → void {}
+static method Extension|set#property6<T extends core::num>(lowered final core::int #this, self::Extension|set#property6::T i) → void {}
 static get Extension|property7() → core::int
   return 0;
 static set Extension|property7(core::int value) → void {}
diff --git a/pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart.weak.expect b/pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart.weak.expect
index 70b4d24..37f68ac 100644
--- a/pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart.weak.expect
@@ -212,7 +212,7 @@
     : super core::Object::•()
     ;
 }
-extension Extension<T extends core::num = core::num> on core::int {
+extension Extension<T extends core::num> on core::int {
   get property1 = self::Extension|get#property1;
   get property2 = self::Extension|get#property2;
   get property3 = self::Extension|get#property3;
@@ -243,35 +243,35 @@
 static get property3() → core::int?
   return 0;
 static set property3(core::int value) → void {}
-static method Extension|get#property1<T extends core::num = core::num>(lowered final core::int #this) → core::int
+static method Extension|get#property1<T extends core::num>(lowered final core::int #this) → core::int
   return 0;
-static method Extension|set#property1<T extends core::num = core::num>(lowered final core::int #this, core::int i) → void {}
-static method Extension|get#property2<T extends core::num = core::num>(lowered final core::int #this) → core::int
+static method Extension|set#property1<T extends core::num>(lowered final core::int #this, core::int i) → void {}
+static method Extension|get#property2<T extends core::num>(lowered final core::int #this) → core::int
   return 0;
-static method Extension|set#property2<T extends core::num = core::num>(lowered final core::int #this, core::int? i) → void {}
-static method Extension|get#property3<T extends core::num = core::num>(lowered final core::int #this) → core::int?
+static method Extension|set#property2<T extends core::num>(lowered final core::int #this, core::int? i) → void {}
+static method Extension|get#property3<T extends core::num>(lowered final core::int #this) → core::int?
   return 0;
-static method Extension|set#property3<T extends core::num = core::num>(lowered final core::int #this, core::int i) → void {}
-static method Extension|get#property4a<T extends core::num = core::num>(lowered final core::int #this) → self::Extension|get#property4a::T
+static method Extension|set#property3<T extends core::num>(lowered final core::int #this, core::int i) → void {}
+static method Extension|get#property4a<T extends core::num>(lowered final core::int #this) → self::Extension|get#property4a::T
   return let final Never #t1 = invalid-expression "pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart:134:23: Error: A value of type 'int' can't be returned from a function with return type 'T'.
   T get property4a => 0; // ok
                       ^" in 0 as{TypeError,ForNonNullableByDefault} Never;
-static method Extension|set#property4a<T extends core::num = core::num>(lowered final core::int #this, self::Extension|set#property4a::T i) → void {}
-static method Extension|get#property4b<T extends core::num = core::num>(lowered final core::int #this) → self::Extension|get#property4b::T?
+static method Extension|set#property4a<T extends core::num>(lowered final core::int #this, self::Extension|set#property4a::T i) → void {}
+static method Extension|get#property4b<T extends core::num>(lowered final core::int #this) → self::Extension|get#property4b::T?
   return let final Never #t2 = invalid-expression "pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart:137:24: Error: A value of type 'int' can't be returned from a function with return type 'T?'.
   T? get property4b => 0; // ok
                        ^" in 0 as{TypeError,ForNonNullableByDefault} Never;
-static method Extension|set#property4b<T extends core::num = core::num>(lowered final core::int #this, self::Extension|set#property4b::T? i) → void {}
-static method Extension|get#property5<T extends core::num = core::num>(lowered final core::int #this) → self::Extension|get#property5::T
+static method Extension|set#property4b<T extends core::num>(lowered final core::int #this, self::Extension|set#property4b::T? i) → void {}
+static method Extension|get#property5<T extends core::num>(lowered final core::int #this) → self::Extension|get#property5::T
   return let final Never #t3 = invalid-expression "pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart:140:22: Error: A value of type 'int' can't be returned from a function with return type 'T'.
   T get property5 => 0; // ok
                      ^" in 0 as{TypeError,ForNonNullableByDefault} Never;
-static method Extension|set#property5<T extends core::num = core::num>(lowered final core::int #this, self::Extension|set#property5::T? i) → void {}
-static method Extension|get#property6<T extends core::num = core::num>(lowered final core::int #this) → self::Extension|get#property6::T?
+static method Extension|set#property5<T extends core::num>(lowered final core::int #this, self::Extension|set#property5::T? i) → void {}
+static method Extension|get#property6<T extends core::num>(lowered final core::int #this) → self::Extension|get#property6::T?
   return let final Never #t4 = invalid-expression "pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart:143:23: Error: A value of type 'int' can't be returned from a function with return type 'T?'.
   T? get property6 => 0; // error
                       ^" in 0 as{TypeError,ForNonNullableByDefault} Never;
-static method Extension|set#property6<T extends core::num = core::num>(lowered final core::int #this, self::Extension|set#property6::T i) → void {}
+static method Extension|set#property6<T extends core::num>(lowered final core::int #this, self::Extension|set#property6::T i) → void {}
 static get Extension|property7() → core::int
   return 0;
 static set Extension|property7(core::int value) → void {}
diff --git a/pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart.weak.outline.expect
index 73e689a..adb8072 100644
--- a/pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart.weak.outline.expect
@@ -190,7 +190,7 @@
   synthetic constructor •() → self::D4
     ;
 }
-extension Extension<T extends core::num = core::num> on core::int {
+extension Extension<T extends core::num> on core::int {
   get property1 = self::Extension|get#property1;
   get property2 = self::Extension|get#property2;
   get property3 = self::Extension|get#property3;
@@ -224,33 +224,33 @@
   ;
 static set property3(core::int value) → void
   ;
-static method Extension|get#property1<T extends core::num = core::num>(lowered final core::int #this) → core::int
+static method Extension|get#property1<T extends core::num>(lowered final core::int #this) → core::int
   ;
-static method Extension|set#property1<T extends core::num = core::num>(lowered final core::int #this, core::int i) → void
+static method Extension|set#property1<T extends core::num>(lowered final core::int #this, core::int i) → void
   ;
-static method Extension|get#property2<T extends core::num = core::num>(lowered final core::int #this) → core::int
+static method Extension|get#property2<T extends core::num>(lowered final core::int #this) → core::int
   ;
-static method Extension|set#property2<T extends core::num = core::num>(lowered final core::int #this, core::int? i) → void
+static method Extension|set#property2<T extends core::num>(lowered final core::int #this, core::int? i) → void
   ;
-static method Extension|get#property3<T extends core::num = core::num>(lowered final core::int #this) → core::int?
+static method Extension|get#property3<T extends core::num>(lowered final core::int #this) → core::int?
   ;
-static method Extension|set#property3<T extends core::num = core::num>(lowered final core::int #this, core::int i) → void
+static method Extension|set#property3<T extends core::num>(lowered final core::int #this, core::int i) → void
   ;
-static method Extension|get#property4a<T extends core::num = core::num>(lowered final core::int #this) → self::Extension|get#property4a::T
+static method Extension|get#property4a<T extends core::num>(lowered final core::int #this) → self::Extension|get#property4a::T
   ;
-static method Extension|set#property4a<T extends core::num = core::num>(lowered final core::int #this, self::Extension|set#property4a::T i) → void
+static method Extension|set#property4a<T extends core::num>(lowered final core::int #this, self::Extension|set#property4a::T i) → void
   ;
-static method Extension|get#property4b<T extends core::num = core::num>(lowered final core::int #this) → self::Extension|get#property4b::T?
+static method Extension|get#property4b<T extends core::num>(lowered final core::int #this) → self::Extension|get#property4b::T?
   ;
-static method Extension|set#property4b<T extends core::num = core::num>(lowered final core::int #this, self::Extension|set#property4b::T? i) → void
+static method Extension|set#property4b<T extends core::num>(lowered final core::int #this, self::Extension|set#property4b::T? i) → void
   ;
-static method Extension|get#property5<T extends core::num = core::num>(lowered final core::int #this) → self::Extension|get#property5::T
+static method Extension|get#property5<T extends core::num>(lowered final core::int #this) → self::Extension|get#property5::T
   ;
-static method Extension|set#property5<T extends core::num = core::num>(lowered final core::int #this, self::Extension|set#property5::T? i) → void
+static method Extension|set#property5<T extends core::num>(lowered final core::int #this, self::Extension|set#property5::T? i) → void
   ;
-static method Extension|get#property6<T extends core::num = core::num>(lowered final core::int #this) → self::Extension|get#property6::T?
+static method Extension|get#property6<T extends core::num>(lowered final core::int #this) → self::Extension|get#property6::T?
   ;
-static method Extension|set#property6<T extends core::num = core::num>(lowered final core::int #this, self::Extension|set#property6::T i) → void
+static method Extension|set#property6<T extends core::num>(lowered final core::int #this, self::Extension|set#property6::T i) → void
   ;
 static get Extension|property7() → core::int
   ;
diff --git a/pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart.weak.transformed.expect
index 70b4d24..37f68ac 100644
--- a/pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart.weak.transformed.expect
@@ -212,7 +212,7 @@
     : super core::Object::•()
     ;
 }
-extension Extension<T extends core::num = core::num> on core::int {
+extension Extension<T extends core::num> on core::int {
   get property1 = self::Extension|get#property1;
   get property2 = self::Extension|get#property2;
   get property3 = self::Extension|get#property3;
@@ -243,35 +243,35 @@
 static get property3() → core::int?
   return 0;
 static set property3(core::int value) → void {}
-static method Extension|get#property1<T extends core::num = core::num>(lowered final core::int #this) → core::int
+static method Extension|get#property1<T extends core::num>(lowered final core::int #this) → core::int
   return 0;
-static method Extension|set#property1<T extends core::num = core::num>(lowered final core::int #this, core::int i) → void {}
-static method Extension|get#property2<T extends core::num = core::num>(lowered final core::int #this) → core::int
+static method Extension|set#property1<T extends core::num>(lowered final core::int #this, core::int i) → void {}
+static method Extension|get#property2<T extends core::num>(lowered final core::int #this) → core::int
   return 0;
-static method Extension|set#property2<T extends core::num = core::num>(lowered final core::int #this, core::int? i) → void {}
-static method Extension|get#property3<T extends core::num = core::num>(lowered final core::int #this) → core::int?
+static method Extension|set#property2<T extends core::num>(lowered final core::int #this, core::int? i) → void {}
+static method Extension|get#property3<T extends core::num>(lowered final core::int #this) → core::int?
   return 0;
-static method Extension|set#property3<T extends core::num = core::num>(lowered final core::int #this, core::int i) → void {}
-static method Extension|get#property4a<T extends core::num = core::num>(lowered final core::int #this) → self::Extension|get#property4a::T
+static method Extension|set#property3<T extends core::num>(lowered final core::int #this, core::int i) → void {}
+static method Extension|get#property4a<T extends core::num>(lowered final core::int #this) → self::Extension|get#property4a::T
   return let final Never #t1 = invalid-expression "pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart:134:23: Error: A value of type 'int' can't be returned from a function with return type 'T'.
   T get property4a => 0; // ok
                       ^" in 0 as{TypeError,ForNonNullableByDefault} Never;
-static method Extension|set#property4a<T extends core::num = core::num>(lowered final core::int #this, self::Extension|set#property4a::T i) → void {}
-static method Extension|get#property4b<T extends core::num = core::num>(lowered final core::int #this) → self::Extension|get#property4b::T?
+static method Extension|set#property4a<T extends core::num>(lowered final core::int #this, self::Extension|set#property4a::T i) → void {}
+static method Extension|get#property4b<T extends core::num>(lowered final core::int #this) → self::Extension|get#property4b::T?
   return let final Never #t2 = invalid-expression "pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart:137:24: Error: A value of type 'int' can't be returned from a function with return type 'T?'.
   T? get property4b => 0; // ok
                        ^" in 0 as{TypeError,ForNonNullableByDefault} Never;
-static method Extension|set#property4b<T extends core::num = core::num>(lowered final core::int #this, self::Extension|set#property4b::T? i) → void {}
-static method Extension|get#property5<T extends core::num = core::num>(lowered final core::int #this) → self::Extension|get#property5::T
+static method Extension|set#property4b<T extends core::num>(lowered final core::int #this, self::Extension|set#property4b::T? i) → void {}
+static method Extension|get#property5<T extends core::num>(lowered final core::int #this) → self::Extension|get#property5::T
   return let final Never #t3 = invalid-expression "pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart:140:22: Error: A value of type 'int' can't be returned from a function with return type 'T'.
   T get property5 => 0; // ok
                      ^" in 0 as{TypeError,ForNonNullableByDefault} Never;
-static method Extension|set#property5<T extends core::num = core::num>(lowered final core::int #this, self::Extension|set#property5::T? i) → void {}
-static method Extension|get#property6<T extends core::num = core::num>(lowered final core::int #this) → self::Extension|get#property6::T?
+static method Extension|set#property5<T extends core::num>(lowered final core::int #this, self::Extension|set#property5::T? i) → void {}
+static method Extension|get#property6<T extends core::num>(lowered final core::int #this) → self::Extension|get#property6::T?
   return let final Never #t4 = invalid-expression "pkg/front_end/testcases/nnbd/getter_vs_setter_type_nnbd.dart:143:23: Error: A value of type 'int' can't be returned from a function with return type 'T?'.
   T? get property6 => 0; // error
                       ^" in 0 as{TypeError,ForNonNullableByDefault} Never;
-static method Extension|set#property6<T extends core::num = core::num>(lowered final core::int #this, self::Extension|set#property6::T i) → void {}
+static method Extension|set#property6<T extends core::num>(lowered final core::int #this, self::Extension|set#property6::T i) → void {}
 static get Extension|property7() → core::int
   return 0;
 static set Extension|property7(core::int value) → void {}
diff --git a/pkg/front_end/testcases/nnbd/infer_object_from_dynamic.dart.strong.expect b/pkg/front_end/testcases/nnbd/infer_object_from_dynamic.dart.strong.expect
index a2932c8..e98b1ac 100644
--- a/pkg/front_end/testcases/nnbd/infer_object_from_dynamic.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/infer_object_from_dynamic.dart.strong.expect
@@ -17,7 +17,7 @@
   return t;
 static method g<T extends core::Object? = dynamic>(self::g::T? t) → self::g::T%
   return t!;
-static method h<T extends core::Object = core::Object>(self::h::T? t) → self::h::T
+static method h<T extends core::Object>(self::h::T? t) → self::h::T
   return t!;
 static method foo(dynamic d, void v, core::Object? onull, core::Object o, core::String? snull, core::String s) → dynamic {
   self::f<dynamic>(d);
diff --git a/pkg/front_end/testcases/nnbd/infer_object_from_dynamic.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/infer_object_from_dynamic.dart.strong.transformed.expect
index a2932c8..e98b1ac 100644
--- a/pkg/front_end/testcases/nnbd/infer_object_from_dynamic.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/infer_object_from_dynamic.dart.strong.transformed.expect
@@ -17,7 +17,7 @@
   return t;
 static method g<T extends core::Object? = dynamic>(self::g::T? t) → self::g::T%
   return t!;
-static method h<T extends core::Object = core::Object>(self::h::T? t) → self::h::T
+static method h<T extends core::Object>(self::h::T? t) → self::h::T
   return t!;
 static method foo(dynamic d, void v, core::Object? onull, core::Object o, core::String? snull, core::String s) → dynamic {
   self::f<dynamic>(d);
diff --git a/pkg/front_end/testcases/nnbd/infer_object_from_dynamic.dart.weak.expect b/pkg/front_end/testcases/nnbd/infer_object_from_dynamic.dart.weak.expect
index a2932c8..e98b1ac 100644
--- a/pkg/front_end/testcases/nnbd/infer_object_from_dynamic.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/infer_object_from_dynamic.dart.weak.expect
@@ -17,7 +17,7 @@
   return t;
 static method g<T extends core::Object? = dynamic>(self::g::T? t) → self::g::T%
   return t!;
-static method h<T extends core::Object = core::Object>(self::h::T? t) → self::h::T
+static method h<T extends core::Object>(self::h::T? t) → self::h::T
   return t!;
 static method foo(dynamic d, void v, core::Object? onull, core::Object o, core::String? snull, core::String s) → dynamic {
   self::f<dynamic>(d);
diff --git a/pkg/front_end/testcases/nnbd/infer_object_from_dynamic.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/infer_object_from_dynamic.dart.weak.outline.expect
index 4238908..ed7979e 100644
--- a/pkg/front_end/testcases/nnbd/infer_object_from_dynamic.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/infer_object_from_dynamic.dart.weak.outline.expect
@@ -6,7 +6,7 @@
   ;
 static method g<T extends core::Object? = dynamic>(self::g::T? t) → self::g::T%
   ;
-static method h<T extends core::Object = core::Object>(self::h::T? t) → self::h::T
+static method h<T extends core::Object>(self::h::T? t) → self::h::T
   ;
 static method foo(dynamic d, void v, core::Object? onull, core::Object o, core::String? snull, core::String s) → dynamic
   ;
diff --git a/pkg/front_end/testcases/nnbd/infer_object_from_dynamic.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/infer_object_from_dynamic.dart.weak.transformed.expect
index a2932c8..e98b1ac 100644
--- a/pkg/front_end/testcases/nnbd/infer_object_from_dynamic.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/infer_object_from_dynamic.dart.weak.transformed.expect
@@ -17,7 +17,7 @@
   return t;
 static method g<T extends core::Object? = dynamic>(self::g::T? t) → self::g::T%
   return t!;
-static method h<T extends core::Object = core::Object>(self::h::T? t) → self::h::T
+static method h<T extends core::Object>(self::h::T? t) → self::h::T
   return t!;
 static method foo(dynamic d, void v, core::Object? onull, core::Object o, core::String? snull, core::String s) → dynamic {
   self::f<dynamic>(d);
diff --git a/pkg/front_end/testcases/nnbd/intersection_types.dart.strong.expect b/pkg/front_end/testcases/nnbd/intersection_types.dart.strong.expect
index 05572ee..aade648 100644
--- a/pkg/front_end/testcases/nnbd/intersection_types.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/intersection_types.dart.strong.expect
@@ -17,7 +17,7 @@
     : super self::B::•()
     ;
 }
-class Foo<T extends self::A? = self::A?> extends core::Object {
+class Foo<T extends self::A?> extends core::Object {
   synthetic constructor •() → self::Foo<self::Foo::T%>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nnbd/intersection_types.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/intersection_types.dart.strong.transformed.expect
index 05572ee..aade648 100644
--- a/pkg/front_end/testcases/nnbd/intersection_types.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/intersection_types.dart.strong.transformed.expect
@@ -17,7 +17,7 @@
     : super self::B::•()
     ;
 }
-class Foo<T extends self::A? = self::A?> extends core::Object {
+class Foo<T extends self::A?> extends core::Object {
   synthetic constructor •() → self::Foo<self::Foo::T%>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nnbd/intersection_types.dart.weak.expect b/pkg/front_end/testcases/nnbd/intersection_types.dart.weak.expect
index 05572ee..aade648 100644
--- a/pkg/front_end/testcases/nnbd/intersection_types.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/intersection_types.dart.weak.expect
@@ -17,7 +17,7 @@
     : super self::B::•()
     ;
 }
-class Foo<T extends self::A? = self::A?> extends core::Object {
+class Foo<T extends self::A?> extends core::Object {
   synthetic constructor •() → self::Foo<self::Foo::T%>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nnbd/intersection_types.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/intersection_types.dart.weak.outline.expect
index 2359ed4..748d6bc 100644
--- a/pkg/front_end/testcases/nnbd/intersection_types.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/intersection_types.dart.weak.outline.expect
@@ -14,7 +14,7 @@
   synthetic constructor •() → self::C
     ;
 }
-class Foo<T extends self::A? = self::A?> extends core::Object {
+class Foo<T extends self::A?> extends core::Object {
   synthetic constructor •() → self::Foo<self::Foo::T%>
     ;
   method doPromotionsToNullable(generic-covariant-impl self::Foo::T% t) → dynamic
diff --git a/pkg/front_end/testcases/nnbd/intersection_types.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/intersection_types.dart.weak.transformed.expect
index 05572ee..aade648 100644
--- a/pkg/front_end/testcases/nnbd/intersection_types.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/intersection_types.dart.weak.transformed.expect
@@ -17,7 +17,7 @@
     : super self::B::•()
     ;
 }
-class Foo<T extends self::A? = self::A?> extends core::Object {
+class Foo<T extends self::A?> extends core::Object {
   synthetic constructor •() → self::Foo<self::Foo::T%>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nnbd/issue40134.dart.strong.expect b/pkg/front_end/testcases/nnbd/issue40134.dart.strong.expect
index 0389f74..c313dbe 100644
--- a/pkg/front_end/testcases/nnbd/issue40134.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/issue40134.dart.strong.expect
@@ -8,18 +8,18 @@
     ;
   get t() → core::Type
     return self::GenericMethodBounds::T%;
-  method foo<generic-covariant-impl E extends self::GenericMethodBounds::T% = self::GenericMethodBounds::T%>() → self::GenericMethodBounds<self::GenericMethodBounds::foo::E%>
+  method foo<generic-covariant-impl E extends self::GenericMethodBounds::T%>() → self::GenericMethodBounds<self::GenericMethodBounds::foo::E%>
     return new self::GenericMethodBounds::•<self::GenericMethodBounds::foo::E%>();
-  method bar<E extends (self::GenericMethodBounds::T%) → void = (self::GenericMethodBounds::T%) → void>() → self::GenericMethodBounds<self::GenericMethodBounds::bar::E>
+  method bar<E extends (self::GenericMethodBounds::T%) → void>() → self::GenericMethodBounds<self::GenericMethodBounds::bar::E>
     return new self::GenericMethodBounds::•<self::GenericMethodBounds::bar::E>();
 }
 class GenericMethodBoundsDerived extends self::GenericMethodBounds<core::num> {
   synthetic constructor •() → self::GenericMethodBoundsDerived
     : super self::GenericMethodBounds::•()
     ;
-  method foo<generic-covariant-impl E extends core::num = core::num>() → self::GenericMethodBounds<self::GenericMethodBoundsDerived::foo::E>
+  method foo<generic-covariant-impl E extends core::num>() → self::GenericMethodBounds<self::GenericMethodBoundsDerived::foo::E>
     return new self::GenericMethodBounds::•<self::GenericMethodBoundsDerived::foo::E>();
-  method bar<E extends (core::num) → void = (core::num) → void>() → self::GenericMethodBounds<self::GenericMethodBoundsDerived::bar::E>
+  method bar<E extends (core::num) → void>() → self::GenericMethodBounds<self::GenericMethodBoundsDerived::bar::E>
     return new self::GenericMethodBounds::•<self::GenericMethodBoundsDerived::bar::E>();
 }
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd/issue40134.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/issue40134.dart.strong.transformed.expect
index 0389f74..c313dbe 100644
--- a/pkg/front_end/testcases/nnbd/issue40134.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue40134.dart.strong.transformed.expect
@@ -8,18 +8,18 @@
     ;
   get t() → core::Type
     return self::GenericMethodBounds::T%;
-  method foo<generic-covariant-impl E extends self::GenericMethodBounds::T% = self::GenericMethodBounds::T%>() → self::GenericMethodBounds<self::GenericMethodBounds::foo::E%>
+  method foo<generic-covariant-impl E extends self::GenericMethodBounds::T%>() → self::GenericMethodBounds<self::GenericMethodBounds::foo::E%>
     return new self::GenericMethodBounds::•<self::GenericMethodBounds::foo::E%>();
-  method bar<E extends (self::GenericMethodBounds::T%) → void = (self::GenericMethodBounds::T%) → void>() → self::GenericMethodBounds<self::GenericMethodBounds::bar::E>
+  method bar<E extends (self::GenericMethodBounds::T%) → void>() → self::GenericMethodBounds<self::GenericMethodBounds::bar::E>
     return new self::GenericMethodBounds::•<self::GenericMethodBounds::bar::E>();
 }
 class GenericMethodBoundsDerived extends self::GenericMethodBounds<core::num> {
   synthetic constructor •() → self::GenericMethodBoundsDerived
     : super self::GenericMethodBounds::•()
     ;
-  method foo<generic-covariant-impl E extends core::num = core::num>() → self::GenericMethodBounds<self::GenericMethodBoundsDerived::foo::E>
+  method foo<generic-covariant-impl E extends core::num>() → self::GenericMethodBounds<self::GenericMethodBoundsDerived::foo::E>
     return new self::GenericMethodBounds::•<self::GenericMethodBoundsDerived::foo::E>();
-  method bar<E extends (core::num) → void = (core::num) → void>() → self::GenericMethodBounds<self::GenericMethodBoundsDerived::bar::E>
+  method bar<E extends (core::num) → void>() → self::GenericMethodBounds<self::GenericMethodBoundsDerived::bar::E>
     return new self::GenericMethodBounds::•<self::GenericMethodBoundsDerived::bar::E>();
 }
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd/issue40134.dart.weak.expect b/pkg/front_end/testcases/nnbd/issue40134.dart.weak.expect
index 0389f74..c313dbe 100644
--- a/pkg/front_end/testcases/nnbd/issue40134.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/issue40134.dart.weak.expect
@@ -8,18 +8,18 @@
     ;
   get t() → core::Type
     return self::GenericMethodBounds::T%;
-  method foo<generic-covariant-impl E extends self::GenericMethodBounds::T% = self::GenericMethodBounds::T%>() → self::GenericMethodBounds<self::GenericMethodBounds::foo::E%>
+  method foo<generic-covariant-impl E extends self::GenericMethodBounds::T%>() → self::GenericMethodBounds<self::GenericMethodBounds::foo::E%>
     return new self::GenericMethodBounds::•<self::GenericMethodBounds::foo::E%>();
-  method bar<E extends (self::GenericMethodBounds::T%) → void = (self::GenericMethodBounds::T%) → void>() → self::GenericMethodBounds<self::GenericMethodBounds::bar::E>
+  method bar<E extends (self::GenericMethodBounds::T%) → void>() → self::GenericMethodBounds<self::GenericMethodBounds::bar::E>
     return new self::GenericMethodBounds::•<self::GenericMethodBounds::bar::E>();
 }
 class GenericMethodBoundsDerived extends self::GenericMethodBounds<core::num> {
   synthetic constructor •() → self::GenericMethodBoundsDerived
     : super self::GenericMethodBounds::•()
     ;
-  method foo<generic-covariant-impl E extends core::num = core::num>() → self::GenericMethodBounds<self::GenericMethodBoundsDerived::foo::E>
+  method foo<generic-covariant-impl E extends core::num>() → self::GenericMethodBounds<self::GenericMethodBoundsDerived::foo::E>
     return new self::GenericMethodBounds::•<self::GenericMethodBoundsDerived::foo::E>();
-  method bar<E extends (core::num) → void = (core::num) → void>() → self::GenericMethodBounds<self::GenericMethodBoundsDerived::bar::E>
+  method bar<E extends (core::num) → void>() → self::GenericMethodBounds<self::GenericMethodBoundsDerived::bar::E>
     return new self::GenericMethodBounds::•<self::GenericMethodBoundsDerived::bar::E>();
 }
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd/issue40134.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/issue40134.dart.weak.outline.expect
index f26dd6e..6c29f77 100644
--- a/pkg/front_end/testcases/nnbd/issue40134.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/issue40134.dart.weak.outline.expect
@@ -7,17 +7,17 @@
     ;
   get t() → core::Type
     ;
-  method foo<generic-covariant-impl E extends self::GenericMethodBounds::T% = self::GenericMethodBounds::T%>() → self::GenericMethodBounds<self::GenericMethodBounds::foo::E%>
+  method foo<generic-covariant-impl E extends self::GenericMethodBounds::T%>() → self::GenericMethodBounds<self::GenericMethodBounds::foo::E%>
     ;
-  method bar<E extends (self::GenericMethodBounds::T%) → void = (self::GenericMethodBounds::T%) → void>() → self::GenericMethodBounds<self::GenericMethodBounds::bar::E>
+  method bar<E extends (self::GenericMethodBounds::T%) → void>() → self::GenericMethodBounds<self::GenericMethodBounds::bar::E>
     ;
 }
 class GenericMethodBoundsDerived extends self::GenericMethodBounds<core::num> {
   synthetic constructor •() → self::GenericMethodBoundsDerived
     ;
-  method foo<generic-covariant-impl E extends core::num = core::num>() → self::GenericMethodBounds<self::GenericMethodBoundsDerived::foo::E>
+  method foo<generic-covariant-impl E extends core::num>() → self::GenericMethodBounds<self::GenericMethodBoundsDerived::foo::E>
     ;
-  method bar<E extends (core::num) → void = (core::num) → void>() → self::GenericMethodBounds<self::GenericMethodBoundsDerived::bar::E>
+  method bar<E extends (core::num) → void>() → self::GenericMethodBounds<self::GenericMethodBoundsDerived::bar::E>
     ;
 }
 static method main() → dynamic
diff --git a/pkg/front_end/testcases/nnbd/issue40134.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/issue40134.dart.weak.transformed.expect
index 0389f74..c313dbe 100644
--- a/pkg/front_end/testcases/nnbd/issue40134.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue40134.dart.weak.transformed.expect
@@ -8,18 +8,18 @@
     ;
   get t() → core::Type
     return self::GenericMethodBounds::T%;
-  method foo<generic-covariant-impl E extends self::GenericMethodBounds::T% = self::GenericMethodBounds::T%>() → self::GenericMethodBounds<self::GenericMethodBounds::foo::E%>
+  method foo<generic-covariant-impl E extends self::GenericMethodBounds::T%>() → self::GenericMethodBounds<self::GenericMethodBounds::foo::E%>
     return new self::GenericMethodBounds::•<self::GenericMethodBounds::foo::E%>();
-  method bar<E extends (self::GenericMethodBounds::T%) → void = (self::GenericMethodBounds::T%) → void>() → self::GenericMethodBounds<self::GenericMethodBounds::bar::E>
+  method bar<E extends (self::GenericMethodBounds::T%) → void>() → self::GenericMethodBounds<self::GenericMethodBounds::bar::E>
     return new self::GenericMethodBounds::•<self::GenericMethodBounds::bar::E>();
 }
 class GenericMethodBoundsDerived extends self::GenericMethodBounds<core::num> {
   synthetic constructor •() → self::GenericMethodBoundsDerived
     : super self::GenericMethodBounds::•()
     ;
-  method foo<generic-covariant-impl E extends core::num = core::num>() → self::GenericMethodBounds<self::GenericMethodBoundsDerived::foo::E>
+  method foo<generic-covariant-impl E extends core::num>() → self::GenericMethodBounds<self::GenericMethodBoundsDerived::foo::E>
     return new self::GenericMethodBounds::•<self::GenericMethodBoundsDerived::foo::E>();
-  method bar<E extends (core::num) → void = (core::num) → void>() → self::GenericMethodBounds<self::GenericMethodBoundsDerived::bar::E>
+  method bar<E extends (core::num) → void>() → self::GenericMethodBounds<self::GenericMethodBoundsDerived::bar::E>
     return new self::GenericMethodBounds::•<self::GenericMethodBoundsDerived::bar::E>();
 }
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd/issue40600.dart.strong.expect b/pkg/front_end/testcases/nnbd/issue40600.dart.strong.expect
index 8e9c78d..ff89535 100644
--- a/pkg/front_end/testcases/nnbd/issue40600.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/issue40600.dart.strong.expect
@@ -26,14 +26,14 @@
   synthetic constructor •() → self::C<self::C::T%>
     : super core::Object::•()
     ;
-  method baz<generic-covariant-impl X extends FutureOr<self::C::T%> = FutureOr<self::C::T%>>(generic-covariant-impl FutureOr<self::C::T%>x) → FutureOr<self::C::T%>
+  method baz<generic-covariant-impl X extends FutureOr<self::C::T%>>(generic-covariant-impl FutureOr<self::C::T%>x) → FutureOr<self::C::T%>
     return x;
 }
 class D<T extends core::Object? = dynamic> extends self::C<self::D::T%> {
   synthetic constructor •() → self::D<self::D::T%>
     : super self::C::•()
     ;
-  method baz<generic-covariant-impl X extends FutureOr<self::D::T%> = FutureOr<self::D::T%>>(generic-covariant-impl FutureOr<self::D::T%>x) → FutureOr<self::D::T%>
+  method baz<generic-covariant-impl X extends FutureOr<self::D::T%>>(generic-covariant-impl FutureOr<self::D::T%>x) → FutureOr<self::D::T%>
     return x;
 }
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd/issue40600.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/issue40600.dart.strong.transformed.expect
index cba6e85..15445a8 100644
--- a/pkg/front_end/testcases/nnbd/issue40600.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue40600.dart.strong.transformed.expect
@@ -26,14 +26,14 @@
   synthetic constructor •() → self::C<self::C::T%>
     : super core::Object::•()
     ;
-  method baz<generic-covariant-impl X extends FutureOr<self::C::T%> = FutureOr<self::C::T%>>(generic-covariant-impl FutureOr<self::C::T%>x) → FutureOr<self::C::T%>
+  method baz<generic-covariant-impl X extends FutureOr<self::C::T%>>(generic-covariant-impl FutureOr<self::C::T%>x) → FutureOr<self::C::T%>
     return x;
 }
 class D<T extends core::Object? = dynamic> extends self::C<self::D::T%> {
   synthetic constructor •() → self::D<self::D::T%>
     : super self::C::•()
     ;
-  method baz<generic-covariant-impl X extends FutureOr<self::D::T%> = FutureOr<self::D::T%>>(generic-covariant-impl FutureOr<self::D::T%>x) → FutureOr<self::D::T%>
+  method baz<generic-covariant-impl X extends FutureOr<self::D::T%>>(generic-covariant-impl FutureOr<self::D::T%>x) → FutureOr<self::D::T%>
     return x;
 }
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd/issue40600.dart.weak.expect b/pkg/front_end/testcases/nnbd/issue40600.dart.weak.expect
index 8e9c78d..ff89535 100644
--- a/pkg/front_end/testcases/nnbd/issue40600.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/issue40600.dart.weak.expect
@@ -26,14 +26,14 @@
   synthetic constructor •() → self::C<self::C::T%>
     : super core::Object::•()
     ;
-  method baz<generic-covariant-impl X extends FutureOr<self::C::T%> = FutureOr<self::C::T%>>(generic-covariant-impl FutureOr<self::C::T%>x) → FutureOr<self::C::T%>
+  method baz<generic-covariant-impl X extends FutureOr<self::C::T%>>(generic-covariant-impl FutureOr<self::C::T%>x) → FutureOr<self::C::T%>
     return x;
 }
 class D<T extends core::Object? = dynamic> extends self::C<self::D::T%> {
   synthetic constructor •() → self::D<self::D::T%>
     : super self::C::•()
     ;
-  method baz<generic-covariant-impl X extends FutureOr<self::D::T%> = FutureOr<self::D::T%>>(generic-covariant-impl FutureOr<self::D::T%>x) → FutureOr<self::D::T%>
+  method baz<generic-covariant-impl X extends FutureOr<self::D::T%>>(generic-covariant-impl FutureOr<self::D::T%>x) → FutureOr<self::D::T%>
     return x;
 }
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd/issue40600.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/issue40600.dart.weak.outline.expect
index 57db9b1..90d1660 100644
--- a/pkg/front_end/testcases/nnbd/issue40600.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/issue40600.dart.weak.outline.expect
@@ -20,13 +20,13 @@
 class C<T extends core::Object? = dynamic> extends core::Object {
   synthetic constructor •() → self::C<self::C::T%>
     ;
-  method baz<generic-covariant-impl X extends FutureOr<self::C::T%> = FutureOr<self::C::T%>>(generic-covariant-impl FutureOr<self::C::T%>x) → FutureOr<self::C::T%>
+  method baz<generic-covariant-impl X extends FutureOr<self::C::T%>>(generic-covariant-impl FutureOr<self::C::T%>x) → FutureOr<self::C::T%>
     ;
 }
 class D<T extends core::Object? = dynamic> extends self::C<self::D::T%> {
   synthetic constructor •() → self::D<self::D::T%>
     ;
-  method baz<generic-covariant-impl X extends FutureOr<self::D::T%> = FutureOr<self::D::T%>>(generic-covariant-impl FutureOr<self::D::T%>x) → FutureOr<self::D::T%>
+  method baz<generic-covariant-impl X extends FutureOr<self::D::T%>>(generic-covariant-impl FutureOr<self::D::T%>x) → FutureOr<self::D::T%>
     ;
 }
 static method main() → dynamic
diff --git a/pkg/front_end/testcases/nnbd/issue40600.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/issue40600.dart.weak.transformed.expect
index cba6e85..15445a8 100644
--- a/pkg/front_end/testcases/nnbd/issue40600.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue40600.dart.weak.transformed.expect
@@ -26,14 +26,14 @@
   synthetic constructor •() → self::C<self::C::T%>
     : super core::Object::•()
     ;
-  method baz<generic-covariant-impl X extends FutureOr<self::C::T%> = FutureOr<self::C::T%>>(generic-covariant-impl FutureOr<self::C::T%>x) → FutureOr<self::C::T%>
+  method baz<generic-covariant-impl X extends FutureOr<self::C::T%>>(generic-covariant-impl FutureOr<self::C::T%>x) → FutureOr<self::C::T%>
     return x;
 }
 class D<T extends core::Object? = dynamic> extends self::C<self::D::T%> {
   synthetic constructor •() → self::D<self::D::T%>
     : super self::C::•()
     ;
-  method baz<generic-covariant-impl X extends FutureOr<self::D::T%> = FutureOr<self::D::T%>>(generic-covariant-impl FutureOr<self::D::T%>x) → FutureOr<self::D::T%>
+  method baz<generic-covariant-impl X extends FutureOr<self::D::T%>>(generic-covariant-impl FutureOr<self::D::T%>x) → FutureOr<self::D::T%>
     return x;
 }
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd/issue41415.dart.strong.expect b/pkg/front_end/testcases/nnbd/issue41415.dart.strong.expect
index 8a8d3f2..818e367a 100644
--- a/pkg/front_end/testcases/nnbd/issue41415.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/issue41415.dart.strong.expect
@@ -3,7 +3,7 @@
 import "dart:core" as core;
 
 static method main() → dynamic {}
-static method test<X extends Null = Null, Y extends Never? = Never?, Z extends Never = Never>() → dynamic {
+static method test<X extends Null, Y extends Never?, Z extends Never>() → dynamic {
   (Null) → core::int f = (core::Object? x) → core::int => 1;
   (Never) → core::int g = (core::Object? x) → core::int => 1;
   (Never?) → core::int h = (core::Object? x) → core::int => 1;
diff --git a/pkg/front_end/testcases/nnbd/issue41415.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/issue41415.dart.strong.transformed.expect
index 8a8d3f2..818e367a 100644
--- a/pkg/front_end/testcases/nnbd/issue41415.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue41415.dart.strong.transformed.expect
@@ -3,7 +3,7 @@
 import "dart:core" as core;
 
 static method main() → dynamic {}
-static method test<X extends Null = Null, Y extends Never? = Never?, Z extends Never = Never>() → dynamic {
+static method test<X extends Null, Y extends Never?, Z extends Never>() → dynamic {
   (Null) → core::int f = (core::Object? x) → core::int => 1;
   (Never) → core::int g = (core::Object? x) → core::int => 1;
   (Never?) → core::int h = (core::Object? x) → core::int => 1;
diff --git a/pkg/front_end/testcases/nnbd/issue41415.dart.weak.expect b/pkg/front_end/testcases/nnbd/issue41415.dart.weak.expect
index 8a8d3f2..818e367a 100644
--- a/pkg/front_end/testcases/nnbd/issue41415.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/issue41415.dart.weak.expect
@@ -3,7 +3,7 @@
 import "dart:core" as core;
 
 static method main() → dynamic {}
-static method test<X extends Null = Null, Y extends Never? = Never?, Z extends Never = Never>() → dynamic {
+static method test<X extends Null, Y extends Never?, Z extends Never>() → dynamic {
   (Null) → core::int f = (core::Object? x) → core::int => 1;
   (Never) → core::int g = (core::Object? x) → core::int => 1;
   (Never?) → core::int h = (core::Object? x) → core::int => 1;
diff --git a/pkg/front_end/testcases/nnbd/issue41415.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/issue41415.dart.weak.outline.expect
index f683084..276ac6a 100644
--- a/pkg/front_end/testcases/nnbd/issue41415.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/issue41415.dart.weak.outline.expect
@@ -3,5 +3,5 @@
 
 static method main() → dynamic
   ;
-static method test<X extends Null = Null, Y extends Never? = Never?, Z extends Never = Never>() → dynamic
+static method test<X extends Null, Y extends Never?, Z extends Never>() → dynamic
   ;
diff --git a/pkg/front_end/testcases/nnbd/issue41415.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/issue41415.dart.weak.transformed.expect
index 8a8d3f2..818e367a 100644
--- a/pkg/front_end/testcases/nnbd/issue41415.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue41415.dart.weak.transformed.expect
@@ -3,7 +3,7 @@
 import "dart:core" as core;
 
 static method main() → dynamic {}
-static method test<X extends Null = Null, Y extends Never? = Never?, Z extends Never = Never>() → dynamic {
+static method test<X extends Null, Y extends Never?, Z extends Never>() → dynamic {
   (Null) → core::int f = (core::Object? x) → core::int => 1;
   (Never) → core::int g = (core::Object? x) → core::int => 1;
   (Never?) → core::int h = (core::Object? x) → core::int => 1;
diff --git a/pkg/front_end/testcases/nnbd/issue41697.dart.strong.expect b/pkg/front_end/testcases/nnbd/issue41697.dart.strong.expect
index 2094805..f04b2c9 100644
--- a/pkg/front_end/testcases/nnbd/issue41697.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/issue41697.dart.strong.expect
@@ -30,26 +30,26 @@
     ;
 }
 static method test1(self::C<core::num> c) → dynamic {
-  <S extends core::num = core::num>(S) → core::num f1 = c.{self::C::field1} = <S extends core::num = core::num>(S s) → core::num {
+  <S extends core::num>(S) → core::num f1 = c.{self::C::field1} = <S extends core::num>(S s) → core::num {
     return s.{core::num::+}(1);
   };
-  <S extends FutureOr<core::num> = FutureOr<core::num>>(S, FutureOr<core::num>) → asy::Future<core::num> f2 = c.{self::C::field2} = <S extends FutureOr<core::num> = FutureOr<core::num>>(S s, FutureOr<core::num>t) → asy::Future<core::num> async {
+  <S extends FutureOr<core::num>>(S, FutureOr<core::num>) → asy::Future<core::num> f2 = c.{self::C::field2} = <S extends FutureOr<core::num>>(S s, FutureOr<core::num>t) → asy::Future<core::num> async {
     return (await t).{core::num::+}(1);
   };
 }
 static method test2(self::C<core::num?> c) → dynamic {
-  <S extends core::num? = core::num?>(S%) → core::num f1 = c.{self::C::field1} = <S extends core::num? = core::num?>(S% s) → core::num {
+  <S extends core::num?>(S%) → core::num f1 = c.{self::C::field1} = <S extends core::num?>(S% s) → core::num {
     return let final Never #t1 = invalid-expression "pkg/front_end/testcases/nnbd/issue41697.dart:33:14: Error: Operator '+' cannot be called on 'S' because it is potentially null.
     return s + 1; // error
              ^" in s.{core::num::+}(1);
   };
-  <S extends FutureOr<core::num?> = FutureOr<core::num?>>(S%, FutureOr<core::num?>) → asy::Future<core::num> f2 = c.{self::C::field2} = <S extends FutureOr<core::num?> = FutureOr<core::num?>>(S% s, FutureOr<core::num?>t) → asy::Future<core::num> async {
+  <S extends FutureOr<core::num?>>(S%, FutureOr<core::num?>) → asy::Future<core::num> f2 = c.{self::C::field2} = <S extends FutureOr<core::num?>>(S% s, FutureOr<core::num?>t) → asy::Future<core::num> async {
     return let final Never #t2 = invalid-expression "pkg/front_end/testcases/nnbd/issue41697.dart:36:22: Error: Operator '+' cannot be called on 'num?' because it is potentially null.
     return (await t) + 1; // error
                      ^" in (await t).{core::num::+}(1);
   };
 }
-static method test3<S extends core::num? = core::num?>(self::test3::S% s) → dynamic
+static method test3<S extends core::num?>(self::test3::S% s) → dynamic
   return let final Never #t3 = invalid-expression "pkg/front_end/testcases/nnbd/issue41697.dart:40:33: Error: Operator '+' cannot be called on 'S' because it is potentially null.
 test3<S extends num?>(S s) => s + 1; // error
                                 ^" in s.{core::num::+}(1);
diff --git a/pkg/front_end/testcases/nnbd/issue41697.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/issue41697.dart.strong.transformed.expect
index 8a37343..7d2ec63 100644
--- a/pkg/front_end/testcases/nnbd/issue41697.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue41697.dart.strong.transformed.expect
@@ -31,10 +31,10 @@
     ;
 }
 static method test1(self::C<core::num> c) → dynamic {
-  <S extends core::num = core::num>(S) → core::num f1 = c.{self::C::field1} = <S extends core::num = core::num>(S s) → core::num {
+  <S extends core::num>(S) → core::num f1 = c.{self::C::field1} = <S extends core::num>(S s) → core::num {
     return s.{core::num::+}(1);
   };
-  <S extends FutureOr<core::num> = FutureOr<core::num>>(S, FutureOr<core::num>) → asy::Future<core::num> f2 = c.{self::C::field2} = <S extends FutureOr<core::num> = FutureOr<core::num>>(S s, FutureOr<core::num>t) → asy::Future<core::num> /* originally async */ {
+  <S extends FutureOr<core::num>>(S, FutureOr<core::num>) → asy::Future<core::num> f2 = c.{self::C::field2} = <S extends FutureOr<core::num>>(S s, FutureOr<core::num>t) → asy::Future<core::num> /* originally async */ {
     final asy::_Future<core::num> :async_future = new asy::_Future::•<core::num>();
     core::bool* :is_sync = false;
     FutureOr<core::num>? :return_value;
@@ -65,12 +65,12 @@
   };
 }
 static method test2(self::C<core::num?> c) → dynamic {
-  <S extends core::num? = core::num?>(S%) → core::num f1 = c.{self::C::field1} = <S extends core::num? = core::num?>(S% s) → core::num {
+  <S extends core::num?>(S%) → core::num f1 = c.{self::C::field1} = <S extends core::num?>(S% s) → core::num {
     return let final Never #t2 = invalid-expression "pkg/front_end/testcases/nnbd/issue41697.dart:33:14: Error: Operator '+' cannot be called on 'S' because it is potentially null.
     return s + 1; // error
              ^" in s.{core::num::+}(1);
   };
-  <S extends FutureOr<core::num?> = FutureOr<core::num?>>(S%, FutureOr<core::num?>) → asy::Future<core::num> f2 = c.{self::C::field2} = <S extends FutureOr<core::num?> = FutureOr<core::num?>>(S% s, FutureOr<core::num?>t) → asy::Future<core::num> /* originally async */ {
+  <S extends FutureOr<core::num?>>(S%, FutureOr<core::num?>) → asy::Future<core::num> f2 = c.{self::C::field2} = <S extends FutureOr<core::num?>>(S% s, FutureOr<core::num?>t) → asy::Future<core::num> /* originally async */ {
     final asy::_Future<core::num> :async_future = new asy::_Future::•<core::num>();
     core::bool* :is_sync = false;
     FutureOr<core::num>? :return_value;
@@ -103,7 +103,7 @@
     return :async_future;
   };
 }
-static method test3<S extends core::num? = core::num?>(self::test3::S% s) → dynamic
+static method test3<S extends core::num?>(self::test3::S% s) → dynamic
   return let final Never #t5 = invalid-expression "pkg/front_end/testcases/nnbd/issue41697.dart:40:33: Error: Operator '+' cannot be called on 'S' because it is potentially null.
 test3<S extends num?>(S s) => s + 1; // error
                                 ^" in s.{core::num::+}(1);
diff --git a/pkg/front_end/testcases/nnbd/issue41697.dart.weak.expect b/pkg/front_end/testcases/nnbd/issue41697.dart.weak.expect
index 2094805..f04b2c9 100644
--- a/pkg/front_end/testcases/nnbd/issue41697.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/issue41697.dart.weak.expect
@@ -30,26 +30,26 @@
     ;
 }
 static method test1(self::C<core::num> c) → dynamic {
-  <S extends core::num = core::num>(S) → core::num f1 = c.{self::C::field1} = <S extends core::num = core::num>(S s) → core::num {
+  <S extends core::num>(S) → core::num f1 = c.{self::C::field1} = <S extends core::num>(S s) → core::num {
     return s.{core::num::+}(1);
   };
-  <S extends FutureOr<core::num> = FutureOr<core::num>>(S, FutureOr<core::num>) → asy::Future<core::num> f2 = c.{self::C::field2} = <S extends FutureOr<core::num> = FutureOr<core::num>>(S s, FutureOr<core::num>t) → asy::Future<core::num> async {
+  <S extends FutureOr<core::num>>(S, FutureOr<core::num>) → asy::Future<core::num> f2 = c.{self::C::field2} = <S extends FutureOr<core::num>>(S s, FutureOr<core::num>t) → asy::Future<core::num> async {
     return (await t).{core::num::+}(1);
   };
 }
 static method test2(self::C<core::num?> c) → dynamic {
-  <S extends core::num? = core::num?>(S%) → core::num f1 = c.{self::C::field1} = <S extends core::num? = core::num?>(S% s) → core::num {
+  <S extends core::num?>(S%) → core::num f1 = c.{self::C::field1} = <S extends core::num?>(S% s) → core::num {
     return let final Never #t1 = invalid-expression "pkg/front_end/testcases/nnbd/issue41697.dart:33:14: Error: Operator '+' cannot be called on 'S' because it is potentially null.
     return s + 1; // error
              ^" in s.{core::num::+}(1);
   };
-  <S extends FutureOr<core::num?> = FutureOr<core::num?>>(S%, FutureOr<core::num?>) → asy::Future<core::num> f2 = c.{self::C::field2} = <S extends FutureOr<core::num?> = FutureOr<core::num?>>(S% s, FutureOr<core::num?>t) → asy::Future<core::num> async {
+  <S extends FutureOr<core::num?>>(S%, FutureOr<core::num?>) → asy::Future<core::num> f2 = c.{self::C::field2} = <S extends FutureOr<core::num?>>(S% s, FutureOr<core::num?>t) → asy::Future<core::num> async {
     return let final Never #t2 = invalid-expression "pkg/front_end/testcases/nnbd/issue41697.dart:36:22: Error: Operator '+' cannot be called on 'num?' because it is potentially null.
     return (await t) + 1; // error
                      ^" in (await t).{core::num::+}(1);
   };
 }
-static method test3<S extends core::num? = core::num?>(self::test3::S% s) → dynamic
+static method test3<S extends core::num?>(self::test3::S% s) → dynamic
   return let final Never #t3 = invalid-expression "pkg/front_end/testcases/nnbd/issue41697.dart:40:33: Error: Operator '+' cannot be called on 'S' because it is potentially null.
 test3<S extends num?>(S s) => s + 1; // error
                                 ^" in s.{core::num::+}(1);
diff --git a/pkg/front_end/testcases/nnbd/issue41697.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/issue41697.dart.weak.outline.expect
index 424dea6..97c9f60 100644
--- a/pkg/front_end/testcases/nnbd/issue41697.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/issue41697.dart.weak.outline.expect
@@ -16,7 +16,7 @@
   ;
 static method test2(self::C<core::num?> c) → dynamic
   ;
-static method test3<S extends core::num? = core::num?>(self::test3::S% s) → dynamic
+static method test3<S extends core::num?>(self::test3::S% s) → dynamic
   ;
 static method main() → dynamic
   ;
diff --git a/pkg/front_end/testcases/nnbd/issue41697.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/issue41697.dart.weak.transformed.expect
index 8a37343..7d2ec63 100644
--- a/pkg/front_end/testcases/nnbd/issue41697.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue41697.dart.weak.transformed.expect
@@ -31,10 +31,10 @@
     ;
 }
 static method test1(self::C<core::num> c) → dynamic {
-  <S extends core::num = core::num>(S) → core::num f1 = c.{self::C::field1} = <S extends core::num = core::num>(S s) → core::num {
+  <S extends core::num>(S) → core::num f1 = c.{self::C::field1} = <S extends core::num>(S s) → core::num {
     return s.{core::num::+}(1);
   };
-  <S extends FutureOr<core::num> = FutureOr<core::num>>(S, FutureOr<core::num>) → asy::Future<core::num> f2 = c.{self::C::field2} = <S extends FutureOr<core::num> = FutureOr<core::num>>(S s, FutureOr<core::num>t) → asy::Future<core::num> /* originally async */ {
+  <S extends FutureOr<core::num>>(S, FutureOr<core::num>) → asy::Future<core::num> f2 = c.{self::C::field2} = <S extends FutureOr<core::num>>(S s, FutureOr<core::num>t) → asy::Future<core::num> /* originally async */ {
     final asy::_Future<core::num> :async_future = new asy::_Future::•<core::num>();
     core::bool* :is_sync = false;
     FutureOr<core::num>? :return_value;
@@ -65,12 +65,12 @@
   };
 }
 static method test2(self::C<core::num?> c) → dynamic {
-  <S extends core::num? = core::num?>(S%) → core::num f1 = c.{self::C::field1} = <S extends core::num? = core::num?>(S% s) → core::num {
+  <S extends core::num?>(S%) → core::num f1 = c.{self::C::field1} = <S extends core::num?>(S% s) → core::num {
     return let final Never #t2 = invalid-expression "pkg/front_end/testcases/nnbd/issue41697.dart:33:14: Error: Operator '+' cannot be called on 'S' because it is potentially null.
     return s + 1; // error
              ^" in s.{core::num::+}(1);
   };
-  <S extends FutureOr<core::num?> = FutureOr<core::num?>>(S%, FutureOr<core::num?>) → asy::Future<core::num> f2 = c.{self::C::field2} = <S extends FutureOr<core::num?> = FutureOr<core::num?>>(S% s, FutureOr<core::num?>t) → asy::Future<core::num> /* originally async */ {
+  <S extends FutureOr<core::num?>>(S%, FutureOr<core::num?>) → asy::Future<core::num> f2 = c.{self::C::field2} = <S extends FutureOr<core::num?>>(S% s, FutureOr<core::num?>t) → asy::Future<core::num> /* originally async */ {
     final asy::_Future<core::num> :async_future = new asy::_Future::•<core::num>();
     core::bool* :is_sync = false;
     FutureOr<core::num>? :return_value;
@@ -103,7 +103,7 @@
     return :async_future;
   };
 }
-static method test3<S extends core::num? = core::num?>(self::test3::S% s) → dynamic
+static method test3<S extends core::num?>(self::test3::S% s) → dynamic
   return let final Never #t5 = invalid-expression "pkg/front_end/testcases/nnbd/issue41697.dart:40:33: Error: Operator '+' cannot be called on 'S' because it is potentially null.
 test3<S extends num?>(S s) => s + 1; // error
                                 ^" in s.{core::num::+}(1);
diff --git a/pkg/front_end/testcases/nnbd/issue41697b.dart.strong.expect b/pkg/front_end/testcases/nnbd/issue41697b.dart.strong.expect
index c4d8855..588916e 100644
--- a/pkg/front_end/testcases/nnbd/issue41697b.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/issue41697b.dart.strong.expect
@@ -13,18 +13,18 @@
 import self as self;
 import "dart:core" as core;
 
-static method test1<S extends core::num = core::num>(self::test1::S s) → dynamic {
+static method test1<S extends core::num>(self::test1::S s) → dynamic {
   core::num t = s.{core::num::+}(1);
 }
-static method test2<S extends core::num? = core::num?>(self::test2::S% s) → dynamic {
+static method test2<S extends core::num?>(self::test2::S% s) → dynamic {
   core::num t = let final Never #t1 = invalid-expression "pkg/front_end/testcases/nnbd/issue41697b.dart:10:13: Error: Operator '+' cannot be called on 'S' because it is potentially null.
   var t = s + 1; // error
             ^" in s.{core::num::+}(1);
 }
-static method test3<S extends core::int = core::int>(self::test3::S s) → dynamic {
+static method test3<S extends core::int>(self::test3::S s) → dynamic {
   core::int t = s.{core::num::+}(1);
 }
-static method test4<S extends core::int? = core::int?>(self::test4::S% s) → dynamic {
+static method test4<S extends core::int?>(self::test4::S% s) → dynamic {
   core::num t = let final Never #t2 = invalid-expression "pkg/front_end/testcases/nnbd/issue41697b.dart:18:13: Error: Operator '+' cannot be called on 'S' because it is potentially null.
   var t = s + 1; // error
             ^" in s.{core::num::+}(1);
diff --git a/pkg/front_end/testcases/nnbd/issue41697b.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/issue41697b.dart.strong.transformed.expect
index c4d8855..588916e 100644
--- a/pkg/front_end/testcases/nnbd/issue41697b.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue41697b.dart.strong.transformed.expect
@@ -13,18 +13,18 @@
 import self as self;
 import "dart:core" as core;
 
-static method test1<S extends core::num = core::num>(self::test1::S s) → dynamic {
+static method test1<S extends core::num>(self::test1::S s) → dynamic {
   core::num t = s.{core::num::+}(1);
 }
-static method test2<S extends core::num? = core::num?>(self::test2::S% s) → dynamic {
+static method test2<S extends core::num?>(self::test2::S% s) → dynamic {
   core::num t = let final Never #t1 = invalid-expression "pkg/front_end/testcases/nnbd/issue41697b.dart:10:13: Error: Operator '+' cannot be called on 'S' because it is potentially null.
   var t = s + 1; // error
             ^" in s.{core::num::+}(1);
 }
-static method test3<S extends core::int = core::int>(self::test3::S s) → dynamic {
+static method test3<S extends core::int>(self::test3::S s) → dynamic {
   core::int t = s.{core::num::+}(1);
 }
-static method test4<S extends core::int? = core::int?>(self::test4::S% s) → dynamic {
+static method test4<S extends core::int?>(self::test4::S% s) → dynamic {
   core::num t = let final Never #t2 = invalid-expression "pkg/front_end/testcases/nnbd/issue41697b.dart:18:13: Error: Operator '+' cannot be called on 'S' because it is potentially null.
   var t = s + 1; // error
             ^" in s.{core::num::+}(1);
diff --git a/pkg/front_end/testcases/nnbd/issue41697b.dart.weak.expect b/pkg/front_end/testcases/nnbd/issue41697b.dart.weak.expect
index c4d8855..588916e 100644
--- a/pkg/front_end/testcases/nnbd/issue41697b.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/issue41697b.dart.weak.expect
@@ -13,18 +13,18 @@
 import self as self;
 import "dart:core" as core;
 
-static method test1<S extends core::num = core::num>(self::test1::S s) → dynamic {
+static method test1<S extends core::num>(self::test1::S s) → dynamic {
   core::num t = s.{core::num::+}(1);
 }
-static method test2<S extends core::num? = core::num?>(self::test2::S% s) → dynamic {
+static method test2<S extends core::num?>(self::test2::S% s) → dynamic {
   core::num t = let final Never #t1 = invalid-expression "pkg/front_end/testcases/nnbd/issue41697b.dart:10:13: Error: Operator '+' cannot be called on 'S' because it is potentially null.
   var t = s + 1; // error
             ^" in s.{core::num::+}(1);
 }
-static method test3<S extends core::int = core::int>(self::test3::S s) → dynamic {
+static method test3<S extends core::int>(self::test3::S s) → dynamic {
   core::int t = s.{core::num::+}(1);
 }
-static method test4<S extends core::int? = core::int?>(self::test4::S% s) → dynamic {
+static method test4<S extends core::int?>(self::test4::S% s) → dynamic {
   core::num t = let final Never #t2 = invalid-expression "pkg/front_end/testcases/nnbd/issue41697b.dart:18:13: Error: Operator '+' cannot be called on 'S' because it is potentially null.
   var t = s + 1; // error
             ^" in s.{core::num::+}(1);
diff --git a/pkg/front_end/testcases/nnbd/issue41697b.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/issue41697b.dart.weak.outline.expect
index f86a56b..af3a068 100644
--- a/pkg/front_end/testcases/nnbd/issue41697b.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/issue41697b.dart.weak.outline.expect
@@ -2,13 +2,13 @@
 import self as self;
 import "dart:core" as core;
 
-static method test1<S extends core::num = core::num>(self::test1::S s) → dynamic
+static method test1<S extends core::num>(self::test1::S s) → dynamic
   ;
-static method test2<S extends core::num? = core::num?>(self::test2::S% s) → dynamic
+static method test2<S extends core::num?>(self::test2::S% s) → dynamic
   ;
-static method test3<S extends core::int = core::int>(self::test3::S s) → dynamic
+static method test3<S extends core::int>(self::test3::S s) → dynamic
   ;
-static method test4<S extends core::int? = core::int?>(self::test4::S% s) → dynamic
+static method test4<S extends core::int?>(self::test4::S% s) → dynamic
   ;
 static method main() → dynamic
   ;
diff --git a/pkg/front_end/testcases/nnbd/issue41697b.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/issue41697b.dart.weak.transformed.expect
index c4d8855..588916e 100644
--- a/pkg/front_end/testcases/nnbd/issue41697b.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue41697b.dart.weak.transformed.expect
@@ -13,18 +13,18 @@
 import self as self;
 import "dart:core" as core;
 
-static method test1<S extends core::num = core::num>(self::test1::S s) → dynamic {
+static method test1<S extends core::num>(self::test1::S s) → dynamic {
   core::num t = s.{core::num::+}(1);
 }
-static method test2<S extends core::num? = core::num?>(self::test2::S% s) → dynamic {
+static method test2<S extends core::num?>(self::test2::S% s) → dynamic {
   core::num t = let final Never #t1 = invalid-expression "pkg/front_end/testcases/nnbd/issue41697b.dart:10:13: Error: Operator '+' cannot be called on 'S' because it is potentially null.
   var t = s + 1; // error
             ^" in s.{core::num::+}(1);
 }
-static method test3<S extends core::int = core::int>(self::test3::S s) → dynamic {
+static method test3<S extends core::int>(self::test3::S s) → dynamic {
   core::int t = s.{core::num::+}(1);
 }
-static method test4<S extends core::int? = core::int?>(self::test4::S% s) → dynamic {
+static method test4<S extends core::int?>(self::test4::S% s) → dynamic {
   core::num t = let final Never #t2 = invalid-expression "pkg/front_end/testcases/nnbd/issue41697b.dart:18:13: Error: Operator '+' cannot be called on 'S' because it is potentially null.
   var t = s + 1; // error
             ^" in s.{core::num::+}(1);
diff --git a/pkg/front_end/testcases/nnbd/issue41952.dart.strong.expect b/pkg/front_end/testcases/nnbd/issue41952.dart.strong.expect
index 01926cd..3952efc 100644
--- a/pkg/front_end/testcases/nnbd/issue41952.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/issue41952.dart.strong.expect
@@ -3,5 +3,5 @@
 import "dart:core" as core;
 
 static method i1<R extends core::Object? = dynamic>() → <S2 extends self::i1::R? = dynamic>() → void
-  return <S2 extends self::i1::R? = self::i1::R?>() → void {};
+  return <S2 extends self::i1::R?>() → void {};
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd/issue41952.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/issue41952.dart.strong.transformed.expect
index 01926cd..3952efc 100644
--- a/pkg/front_end/testcases/nnbd/issue41952.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue41952.dart.strong.transformed.expect
@@ -3,5 +3,5 @@
 import "dart:core" as core;
 
 static method i1<R extends core::Object? = dynamic>() → <S2 extends self::i1::R? = dynamic>() → void
-  return <S2 extends self::i1::R? = self::i1::R?>() → void {};
+  return <S2 extends self::i1::R?>() → void {};
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd/issue41952.dart.weak.expect b/pkg/front_end/testcases/nnbd/issue41952.dart.weak.expect
index 01926cd..3952efc 100644
--- a/pkg/front_end/testcases/nnbd/issue41952.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/issue41952.dart.weak.expect
@@ -3,5 +3,5 @@
 import "dart:core" as core;
 
 static method i1<R extends core::Object? = dynamic>() → <S2 extends self::i1::R? = dynamic>() → void
-  return <S2 extends self::i1::R? = self::i1::R?>() → void {};
+  return <S2 extends self::i1::R?>() → void {};
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd/issue41952.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/issue41952.dart.weak.transformed.expect
index 01926cd..3952efc 100644
--- a/pkg/front_end/testcases/nnbd/issue41952.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue41952.dart.weak.transformed.expect
@@ -3,5 +3,5 @@
 import "dart:core" as core;
 
 static method i1<R extends core::Object? = dynamic>() → <S2 extends self::i1::R? = dynamic>() → void
-  return <S2 extends self::i1::R? = self::i1::R?>() → void {};
+  return <S2 extends self::i1::R?>() → void {};
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd/issue42429.dart.strong.expect b/pkg/front_end/testcases/nnbd/issue42429.dart.strong.expect
index 77cfde0..717c859 100644
--- a/pkg/front_end/testcases/nnbd/issue42429.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/issue42429.dart.strong.expect
@@ -195,11 +195,11 @@
 import self as self;
 import "dart:core" as core;
 
-typedef FArgument<contravariant X extends core::num = core::num> = (X) → dynamic;
-typedef FReturn<X extends core::num = core::num> = () → X;
-typedef FBoth<invariant X extends core::num = core::num> = (X) → X;
-typedef FNowhere<unrelated X extends core::num = core::num> = () → dynamic;
-class A<T extends core::num = core::num> extends core::Object {
+typedef FArgument<contravariant X extends core::num> = (X) → dynamic;
+typedef FReturn<X extends core::num> = () → X;
+typedef FBoth<invariant X extends core::num> = (X) → X;
+typedef FNowhere<unrelated X extends core::num> = () → dynamic;
+class A<T extends core::num> extends core::Object {
   synthetic constructor •() → self::A<self::A::T>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nnbd/issue42429.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/issue42429.dart.strong.transformed.expect
index 77cfde0..717c859 100644
--- a/pkg/front_end/testcases/nnbd/issue42429.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue42429.dart.strong.transformed.expect
@@ -195,11 +195,11 @@
 import self as self;
 import "dart:core" as core;
 
-typedef FArgument<contravariant X extends core::num = core::num> = (X) → dynamic;
-typedef FReturn<X extends core::num = core::num> = () → X;
-typedef FBoth<invariant X extends core::num = core::num> = (X) → X;
-typedef FNowhere<unrelated X extends core::num = core::num> = () → dynamic;
-class A<T extends core::num = core::num> extends core::Object {
+typedef FArgument<contravariant X extends core::num> = (X) → dynamic;
+typedef FReturn<X extends core::num> = () → X;
+typedef FBoth<invariant X extends core::num> = (X) → X;
+typedef FNowhere<unrelated X extends core::num> = () → dynamic;
+class A<T extends core::num> extends core::Object {
   synthetic constructor •() → self::A<self::A::T>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nnbd/issue42429.dart.weak.expect b/pkg/front_end/testcases/nnbd/issue42429.dart.weak.expect
index 77cfde0..717c859 100644
--- a/pkg/front_end/testcases/nnbd/issue42429.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/issue42429.dart.weak.expect
@@ -195,11 +195,11 @@
 import self as self;
 import "dart:core" as core;
 
-typedef FArgument<contravariant X extends core::num = core::num> = (X) → dynamic;
-typedef FReturn<X extends core::num = core::num> = () → X;
-typedef FBoth<invariant X extends core::num = core::num> = (X) → X;
-typedef FNowhere<unrelated X extends core::num = core::num> = () → dynamic;
-class A<T extends core::num = core::num> extends core::Object {
+typedef FArgument<contravariant X extends core::num> = (X) → dynamic;
+typedef FReturn<X extends core::num> = () → X;
+typedef FBoth<invariant X extends core::num> = (X) → X;
+typedef FNowhere<unrelated X extends core::num> = () → dynamic;
+class A<T extends core::num> extends core::Object {
   synthetic constructor •() → self::A<self::A::T>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nnbd/issue42429.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/issue42429.dart.weak.outline.expect
index 2034770..d17a02c 100644
--- a/pkg/front_end/testcases/nnbd/issue42429.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/issue42429.dart.weak.outline.expect
@@ -2,11 +2,11 @@
 import self as self;
 import "dart:core" as core;
 
-typedef FArgument<contravariant X extends core::num = core::num> = (X) → dynamic;
-typedef FReturn<X extends core::num = core::num> = () → X;
-typedef FBoth<invariant X extends core::num = core::num> = (X) → X;
-typedef FNowhere<unrelated X extends core::num = core::num> = () → dynamic;
-class A<T extends core::num = core::num> extends core::Object {
+typedef FArgument<contravariant X extends core::num> = (X) → dynamic;
+typedef FReturn<X extends core::num> = () → X;
+typedef FBoth<invariant X extends core::num> = (X) → X;
+typedef FNowhere<unrelated X extends core::num> = () → dynamic;
+class A<T extends core::num> extends core::Object {
   synthetic constructor •() → self::A<self::A::T>
     ;
 }
diff --git a/pkg/front_end/testcases/nnbd/issue42429.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/issue42429.dart.weak.transformed.expect
index 77cfde0..717c859 100644
--- a/pkg/front_end/testcases/nnbd/issue42429.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue42429.dart.weak.transformed.expect
@@ -195,11 +195,11 @@
 import self as self;
 import "dart:core" as core;
 
-typedef FArgument<contravariant X extends core::num = core::num> = (X) → dynamic;
-typedef FReturn<X extends core::num = core::num> = () → X;
-typedef FBoth<invariant X extends core::num = core::num> = (X) → X;
-typedef FNowhere<unrelated X extends core::num = core::num> = () → dynamic;
-class A<T extends core::num = core::num> extends core::Object {
+typedef FArgument<contravariant X extends core::num> = (X) → dynamic;
+typedef FReturn<X extends core::num> = () → X;
+typedef FBoth<invariant X extends core::num> = (X) → X;
+typedef FNowhere<unrelated X extends core::num> = () → dynamic;
+class A<T extends core::num> extends core::Object {
   synthetic constructor •() → self::A<self::A::T>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nnbd/issue42433.dart.strong.expect b/pkg/front_end/testcases/nnbd/issue42433.dart.strong.expect
index db8fd3e..2d7f2f7 100644
--- a/pkg/front_end/testcases/nnbd/issue42433.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/issue42433.dart.strong.expect
@@ -2,13 +2,13 @@
 import self as self;
 import "dart:core" as core;
 
-typedef Test<contravariant T extends self::X = self::X> = (T?) → dynamic;
+typedef Test<contravariant T extends self::X> = (T?) → dynamic;
 class X extends core::Object {
   synthetic constructor •() → self::X
     : super core::Object::•()
     ;
 }
-static method checkme<T extends self::X = self::X>(self::checkme::T? t) → dynamic {}
+static method checkme<T extends self::X>(self::checkme::T? t) → dynamic {}
 static method main() → dynamic {
   (self::X?) → dynamic t2 = #C1<self::X>;
 }
diff --git a/pkg/front_end/testcases/nnbd/issue42433.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/issue42433.dart.strong.transformed.expect
index 87a95fd..bb2b62a 100644
--- a/pkg/front_end/testcases/nnbd/issue42433.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue42433.dart.strong.transformed.expect
@@ -2,13 +2,13 @@
 import self as self;
 import "dart:core" as core;
 
-typedef Test<contravariant T extends self::X = self::X> = (T?) → dynamic;
+typedef Test<contravariant T extends self::X> = (T?) → dynamic;
 class X extends core::Object {
   synthetic constructor •() → self::X
     : super core::Object::•()
     ;
 }
-static method checkme<T extends self::X = self::X>(self::checkme::T? t) → dynamic {}
+static method checkme<T extends self::X>(self::checkme::T? t) → dynamic {}
 static method main() → dynamic {
   (self::X?) → dynamic t2 = #C1<self::X>;
 }
diff --git a/pkg/front_end/testcases/nnbd/issue42433.dart.weak.expect b/pkg/front_end/testcases/nnbd/issue42433.dart.weak.expect
index db8fd3e..2d7f2f7 100644
--- a/pkg/front_end/testcases/nnbd/issue42433.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/issue42433.dart.weak.expect
@@ -2,13 +2,13 @@
 import self as self;
 import "dart:core" as core;
 
-typedef Test<contravariant T extends self::X = self::X> = (T?) → dynamic;
+typedef Test<contravariant T extends self::X> = (T?) → dynamic;
 class X extends core::Object {
   synthetic constructor •() → self::X
     : super core::Object::•()
     ;
 }
-static method checkme<T extends self::X = self::X>(self::checkme::T? t) → dynamic {}
+static method checkme<T extends self::X>(self::checkme::T? t) → dynamic {}
 static method main() → dynamic {
   (self::X?) → dynamic t2 = #C1<self::X>;
 }
diff --git a/pkg/front_end/testcases/nnbd/issue42433.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/issue42433.dart.weak.outline.expect
index 3c8de2a..ffd1301 100644
--- a/pkg/front_end/testcases/nnbd/issue42433.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/issue42433.dart.weak.outline.expect
@@ -2,12 +2,12 @@
 import self as self;
 import "dart:core" as core;
 
-typedef Test<contravariant T extends self::X = self::X> = (T?) → dynamic;
+typedef Test<contravariant T extends self::X> = (T?) → dynamic;
 class X extends core::Object {
   synthetic constructor •() → self::X
     ;
 }
-static method checkme<T extends self::X = self::X>(self::checkme::T? t) → dynamic
+static method checkme<T extends self::X>(self::checkme::T? t) → dynamic
   ;
 static method main() → dynamic
   ;
diff --git a/pkg/front_end/testcases/nnbd/issue42433.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/issue42433.dart.weak.transformed.expect
index 7c42561..4754890 100644
--- a/pkg/front_end/testcases/nnbd/issue42433.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue42433.dart.weak.transformed.expect
@@ -2,13 +2,13 @@
 import self as self;
 import "dart:core" as core;
 
-typedef Test<contravariant T extends self::X = self::X> = (T?) → dynamic;
+typedef Test<contravariant T extends self::X> = (T?) → dynamic;
 class X extends core::Object {
   synthetic constructor •() → self::X
     : super core::Object::•()
     ;
 }
-static method checkme<T extends self::X = self::X>(self::checkme::T? t) → dynamic {}
+static method checkme<T extends self::X>(self::checkme::T? t) → dynamic {}
 static method main() → dynamic {
   (self::X?) → dynamic t2 = #C1<self::X>;
 }
diff --git a/pkg/front_end/testcases/nnbd/issue42758.dart.strong.expect b/pkg/front_end/testcases/nnbd/issue42758.dart.strong.expect
index 5370148..d04548d 100644
--- a/pkg/front_end/testcases/nnbd/issue42758.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/issue42758.dart.strong.expect
@@ -182,7 +182,7 @@
     #t25.{core::Map::[]=}{Invariant}(n1, n1);
   } =>#t25;
 }
-static method test2<N1 extends Never = Never, N2 extends Never? = Never?, N3 extends Null = Null>(self::test2::N1 n1, self::test2::N2% n2, self::test2::N3% n3) → dynamic {
+static method test2<N1 extends Never, N2 extends Never?, N3 extends Null>(self::test2::N1 n1, self::test2::N2% n2, self::test2::N3% n3) → dynamic {
   core::List<Never> l1 = block {
     final core::List<Never> #t28 = core::List::of<Never>(n1);
   } =>#t28;
diff --git a/pkg/front_end/testcases/nnbd/issue42758.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/issue42758.dart.strong.transformed.expect
index 58a9aad..57f8fe1 100644
--- a/pkg/front_end/testcases/nnbd/issue42758.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue42758.dart.strong.transformed.expect
@@ -199,7 +199,7 @@
     #t25.{core::Map::[]=}{Invariant}(n1, n1);
   } =>#t25;
 }
-static method test2<N1 extends Never = Never, N2 extends Never? = Never?, N3 extends Null = Null>(self::test2::N1 n1, self::test2::N2% n2, self::test2::N3% n3) → dynamic {
+static method test2<N1 extends Never, N2 extends Never?, N3 extends Null>(self::test2::N1 n1, self::test2::N2% n2, self::test2::N3% n3) → dynamic {
   core::List<Never> l1 = block {
     final core::List<Never> #t28 = core::List::of<Never>(n1);
   } =>#t28;
diff --git a/pkg/front_end/testcases/nnbd/issue42758.dart.weak.expect b/pkg/front_end/testcases/nnbd/issue42758.dart.weak.expect
index 79c5408..0eb909b 100644
--- a/pkg/front_end/testcases/nnbd/issue42758.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/issue42758.dart.weak.expect
@@ -183,7 +183,7 @@
     #t47.{core::Map::[]=}{Invariant}(let final Never #t50 = n1 in throw new _in::ReachabilityError::•("`null` encountered as the result from expression with type `Never`."), let final Never #t51 = n1 in throw new _in::ReachabilityError::•("`null` encountered as the result from expression with type `Never`."));
   } =>#t47;
 }
-static method test2<N1 extends Never = Never, N2 extends Never? = Never?, N3 extends Null = Null>(self::test2::N1 n1, self::test2::N2% n2, self::test2::N3% n3) → dynamic {
+static method test2<N1 extends Never, N2 extends Never?, N3 extends Null>(self::test2::N1 n1, self::test2::N2% n2, self::test2::N3% n3) → dynamic {
   core::List<Never> l1 = block {
     final core::List<Never> #t52 = core::List::of<Never>(let final self::test2::N1 #t53 = n1 in throw new _in::ReachabilityError::•("`null` encountered as the result from expression with type `Never`."));
   } =>#t52;
diff --git a/pkg/front_end/testcases/nnbd/issue42758.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/issue42758.dart.weak.outline.expect
index d2e2ef3..f2ca1af 100644
--- a/pkg/front_end/testcases/nnbd/issue42758.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/issue42758.dart.weak.outline.expect
@@ -3,7 +3,7 @@
 
 static method test1(Never n1, Never? n2, Null n3) → dynamic
   ;
-static method test2<N1 extends Never = Never, N2 extends Never? = Never?, N3 extends Null = Null>(self::test2::N1 n1, self::test2::N2% n2, self::test2::N3% n3) → dynamic
+static method test2<N1 extends Never, N2 extends Never?, N3 extends Null>(self::test2::N1 n1, self::test2::N2% n2, self::test2::N3% n3) → dynamic
   ;
 static method main() → dynamic
   ;
diff --git a/pkg/front_end/testcases/nnbd/issue42758.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/issue42758.dart.weak.transformed.expect
index 6e5b756..645b792 100644
--- a/pkg/front_end/testcases/nnbd/issue42758.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue42758.dart.weak.transformed.expect
@@ -200,7 +200,7 @@
     #t47.{core::Map::[]=}{Invariant}(let final Never #t50 = n1 in throw new _in::ReachabilityError::•("`null` encountered as the result from expression with type `Never`."), let final Never #t51 = n1 in throw new _in::ReachabilityError::•("`null` encountered as the result from expression with type `Never`."));
   } =>#t47;
 }
-static method test2<N1 extends Never = Never, N2 extends Never? = Never?, N3 extends Null = Null>(self::test2::N1 n1, self::test2::N2% n2, self::test2::N3% n3) → dynamic {
+static method test2<N1 extends Never, N2 extends Never?, N3 extends Null>(self::test2::N1 n1, self::test2::N2% n2, self::test2::N3% n3) → dynamic {
   core::List<Never> l1 = block {
     final core::List<Never> #t52 = core::List::of<Never>(let final self::test2::N1 #t53 = n1 in throw new _in::ReachabilityError::•("`null` encountered as the result from expression with type `Never`."));
   } =>#t52;
diff --git a/pkg/front_end/testcases/nnbd/issue43211.dart.strong.expect b/pkg/front_end/testcases/nnbd/issue43211.dart.strong.expect
index 39c2e9c..19e109d 100644
--- a/pkg/front_end/testcases/nnbd/issue43211.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/issue43211.dart.strong.expect
@@ -202,20 +202,20 @@
     : super core::Object::•()
     ;
 }
-class D<X extends core::num = core::num> extends core::Object {
+class D<X extends core::num> extends core::Object {
   synthetic constructor •() → self::D<self::D::X>
     : super core::Object::•()
     ;
 }
-class B<X extends self::A<Null>? = self::A<Null>?> extends core::Object implements self::A<self::B::X%> {
+class B<X extends self::A<Null>?> extends core::Object implements self::A<self::B::X%> {
   synthetic constructor •() → self::B<self::B::X%>
     : super core::Object::•()
     ;
-  method method1<Y extends self::A<Null>? = self::A<Null>?>(self::A<self::B::method1::Y%> a, self::A<self::A<Null>>? b) → void {
+  method method1<Y extends self::A<Null>?>(self::A<self::B::method1::Y%> a, self::A<self::A<Null>>? b) → void {
     self::A<self::B::method1::Y%>? c;
     self::A<self::A<Null>>? d;
   }
-  method method2<Y extends core::String = core::String>(self::D<self::B::method2::Y> a, self::D<core::String>? b) → void {
+  method method2<Y extends core::String>(self::D<self::B::method2::Y> a, self::D<core::String>? b) → void {
     self::D<self::B::method2::Y>? c;
     self::D<core::String>? d;
   }
@@ -241,7 +241,7 @@
   method method2 = self::Extension1|method2;
   tearoff method2 = self::Extension1|get#method2;
 }
-extension ext2<X extends self::A<Null>? = self::A<Null>?> on self::A<X%> {
+extension ext2<X extends self::A<Null>?> on self::A<X%> {
 }
 static method Extension1|method1<X extends self::A<self::Extension1|method1::X%>? = self::A<dynamic>?, Y extends self::A<self::Extension1|method1::Y%>? = self::A<dynamic>?>(lowered final self::A<self::Extension1|method1::X%> #this, self::A<self::Extension1|method1::Y%> a, self::A<self::A<Null>>? b) → void {
   self::A<self::Extension1|method1::Y%>? c;
@@ -249,12 +249,12 @@
 }
 static method Extension1|get#method1<X extends self::A<self::Extension1|get#method1::X%>? = self::A<dynamic>?>(lowered final self::A<self::Extension1|get#method1::X%> #this) → <Y extends self::A<Y%>? = self::A<dynamic>?>(self::A<Y%>, self::A<self::A<Null>>?) → void
   return <Y extends self::A<Y%>? = self::A<dynamic>?>(self::A<Y%> a, self::A<self::A<Null>>? b) → void => self::Extension1|method1<self::Extension1|get#method1::X%, Y%>(#this, a, b);
-static method Extension1|method2<X extends self::A<self::Extension1|method2::X%>? = self::A<dynamic>?, Y extends core::String = core::String>(lowered final self::A<self::Extension1|method2::X%> #this, self::D<self::Extension1|method2::Y> a, self::D<core::String>? b) → void {
+static method Extension1|method2<X extends self::A<self::Extension1|method2::X%>? = self::A<dynamic>?, Y extends core::String>(lowered final self::A<self::Extension1|method2::X%> #this, self::D<self::Extension1|method2::Y> a, self::D<core::String>? b) → void {
   self::D<self::Extension1|method2::Y>? c;
   self::D<core::String>? d;
 }
-static method Extension1|get#method2<X extends self::A<self::Extension1|get#method2::X%>? = self::A<dynamic>?>(lowered final self::A<self::Extension1|get#method2::X%> #this) → <Y extends core::String = core::String>(self::D<Y>, self::D<core::String>?) → void
-  return <Y extends core::String = core::String>(self::D<Y> a, self::D<core::String>? b) → void => self::Extension1|method2<self::Extension1|get#method2::X%, Y>(#this, a, b);
+static method Extension1|get#method2<X extends self::A<self::Extension1|get#method2::X%>? = self::A<dynamic>?>(lowered final self::A<self::Extension1|get#method2::X%> #this) → <Y extends core::String>(self::D<Y>, self::D<core::String>?) → void
+  return <Y extends core::String>(self::D<Y> a, self::D<core::String>? b) → void => self::Extension1|method2<self::Extension1|get#method2::X%, Y>(#this, a, b);
 static method test() → dynamic {
   self::A<Null> a = new self::A::•<Null>();
 }
diff --git a/pkg/front_end/testcases/nnbd/issue43211.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/issue43211.dart.strong.transformed.expect
index 0fcf8ea..48a5a0a 100644
--- a/pkg/front_end/testcases/nnbd/issue43211.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue43211.dart.strong.transformed.expect
@@ -202,20 +202,20 @@
     : super core::Object::•()
     ;
 }
-class D<X extends core::num = core::num> extends core::Object {
+class D<X extends core::num> extends core::Object {
   synthetic constructor •() → self::D<self::D::X>
     : super core::Object::•()
     ;
 }
-class B<X extends self::A<Null>? = self::A<Null>?> extends core::Object implements self::A<self::B::X%> {
+class B<X extends self::A<Null>?> extends core::Object implements self::A<self::B::X%> {
   synthetic constructor •() → self::B<self::B::X%>
     : super core::Object::•()
     ;
-  method method1<Y extends self::A<Null>? = self::A<Null>?>(self::A<self::B::method1::Y%> a, self::A<self::A<Null>>? b) → void {
+  method method1<Y extends self::A<Null>?>(self::A<self::B::method1::Y%> a, self::A<self::A<Null>>? b) → void {
     self::A<self::B::method1::Y%>? c;
     self::A<self::A<Null>>? d;
   }
-  method method2<Y extends core::String = core::String>(self::D<self::B::method2::Y> a, self::D<core::String>? b) → void {
+  method method2<Y extends core::String>(self::D<self::B::method2::Y> a, self::D<core::String>? b) → void {
     self::D<self::B::method2::Y>? c;
     self::D<core::String>? d;
   }
@@ -241,7 +241,7 @@
   method method2 = self::Extension1|method2;
   tearoff method2 = self::Extension1|get#method2;
 }
-extension ext2<X extends self::A<Null>? = self::A<Null>?> on self::A<X%> {
+extension ext2<X extends self::A<Null>?> on self::A<X%> {
 }
 static method Extension1|method1<X extends self::A<self::Extension1|method1::X%>? = self::A<dynamic>?, Y extends self::A<self::Extension1|method1::Y%>? = self::A<dynamic>?>(lowered final self::A<self::Extension1|method1::X%> #this, self::A<self::Extension1|method1::Y%> a, self::A<self::A<Null>>? b) → void {
   self::A<self::Extension1|method1::Y%>? c;
@@ -249,12 +249,12 @@
 }
 static method Extension1|get#method1<X extends self::A<self::Extension1|get#method1::X%>? = self::A<dynamic>?>(lowered final self::A<self::Extension1|get#method1::X%> #this) → <Y extends self::A<Y%>? = self::A<dynamic>?>(self::A<Y%>, self::A<self::A<Null>>?) → void
   return <Y extends self::A<Y%>? = self::A<dynamic>?>(self::A<Y%> a, self::A<self::A<Null>>? b) → void => self::Extension1|method1<self::Extension1|get#method1::X%, Y%>(#this, a, b);
-static method Extension1|method2<X extends self::A<self::Extension1|method2::X%>? = self::A<dynamic>?, Y extends core::String = core::String>(lowered final self::A<self::Extension1|method2::X%> #this, self::D<self::Extension1|method2::Y> a, self::D<core::String>? b) → void {
+static method Extension1|method2<X extends self::A<self::Extension1|method2::X%>? = self::A<dynamic>?, Y extends core::String>(lowered final self::A<self::Extension1|method2::X%> #this, self::D<self::Extension1|method2::Y> a, self::D<core::String>? b) → void {
   self::D<self::Extension1|method2::Y>? c;
   self::D<core::String>? d;
 }
-static method Extension1|get#method2<X extends self::A<self::Extension1|get#method2::X%>? = self::A<dynamic>?>(lowered final self::A<self::Extension1|get#method2::X%> #this) → <Y extends core::String = core::String>(self::D<Y>, self::D<core::String>?) → void
-  return <Y extends core::String = core::String>(self::D<Y> a, self::D<core::String>? b) → void => self::Extension1|method2<self::Extension1|get#method2::X%, Y>(#this, a, b);
+static method Extension1|get#method2<X extends self::A<self::Extension1|get#method2::X%>? = self::A<dynamic>?>(lowered final self::A<self::Extension1|get#method2::X%> #this) → <Y extends core::String>(self::D<Y>, self::D<core::String>?) → void
+  return <Y extends core::String>(self::D<Y> a, self::D<core::String>? b) → void => self::Extension1|method2<self::Extension1|get#method2::X%, Y>(#this, a, b);
 static method test() → dynamic {
   self::A<Null> a = new self::A::•<Null>();
 }
diff --git a/pkg/front_end/testcases/nnbd/issue43211.dart.weak.expect b/pkg/front_end/testcases/nnbd/issue43211.dart.weak.expect
index 39c2e9c..19e109d 100644
--- a/pkg/front_end/testcases/nnbd/issue43211.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/issue43211.dart.weak.expect
@@ -202,20 +202,20 @@
     : super core::Object::•()
     ;
 }
-class D<X extends core::num = core::num> extends core::Object {
+class D<X extends core::num> extends core::Object {
   synthetic constructor •() → self::D<self::D::X>
     : super core::Object::•()
     ;
 }
-class B<X extends self::A<Null>? = self::A<Null>?> extends core::Object implements self::A<self::B::X%> {
+class B<X extends self::A<Null>?> extends core::Object implements self::A<self::B::X%> {
   synthetic constructor •() → self::B<self::B::X%>
     : super core::Object::•()
     ;
-  method method1<Y extends self::A<Null>? = self::A<Null>?>(self::A<self::B::method1::Y%> a, self::A<self::A<Null>>? b) → void {
+  method method1<Y extends self::A<Null>?>(self::A<self::B::method1::Y%> a, self::A<self::A<Null>>? b) → void {
     self::A<self::B::method1::Y%>? c;
     self::A<self::A<Null>>? d;
   }
-  method method2<Y extends core::String = core::String>(self::D<self::B::method2::Y> a, self::D<core::String>? b) → void {
+  method method2<Y extends core::String>(self::D<self::B::method2::Y> a, self::D<core::String>? b) → void {
     self::D<self::B::method2::Y>? c;
     self::D<core::String>? d;
   }
@@ -241,7 +241,7 @@
   method method2 = self::Extension1|method2;
   tearoff method2 = self::Extension1|get#method2;
 }
-extension ext2<X extends self::A<Null>? = self::A<Null>?> on self::A<X%> {
+extension ext2<X extends self::A<Null>?> on self::A<X%> {
 }
 static method Extension1|method1<X extends self::A<self::Extension1|method1::X%>? = self::A<dynamic>?, Y extends self::A<self::Extension1|method1::Y%>? = self::A<dynamic>?>(lowered final self::A<self::Extension1|method1::X%> #this, self::A<self::Extension1|method1::Y%> a, self::A<self::A<Null>>? b) → void {
   self::A<self::Extension1|method1::Y%>? c;
@@ -249,12 +249,12 @@
 }
 static method Extension1|get#method1<X extends self::A<self::Extension1|get#method1::X%>? = self::A<dynamic>?>(lowered final self::A<self::Extension1|get#method1::X%> #this) → <Y extends self::A<Y%>? = self::A<dynamic>?>(self::A<Y%>, self::A<self::A<Null>>?) → void
   return <Y extends self::A<Y%>? = self::A<dynamic>?>(self::A<Y%> a, self::A<self::A<Null>>? b) → void => self::Extension1|method1<self::Extension1|get#method1::X%, Y%>(#this, a, b);
-static method Extension1|method2<X extends self::A<self::Extension1|method2::X%>? = self::A<dynamic>?, Y extends core::String = core::String>(lowered final self::A<self::Extension1|method2::X%> #this, self::D<self::Extension1|method2::Y> a, self::D<core::String>? b) → void {
+static method Extension1|method2<X extends self::A<self::Extension1|method2::X%>? = self::A<dynamic>?, Y extends core::String>(lowered final self::A<self::Extension1|method2::X%> #this, self::D<self::Extension1|method2::Y> a, self::D<core::String>? b) → void {
   self::D<self::Extension1|method2::Y>? c;
   self::D<core::String>? d;
 }
-static method Extension1|get#method2<X extends self::A<self::Extension1|get#method2::X%>? = self::A<dynamic>?>(lowered final self::A<self::Extension1|get#method2::X%> #this) → <Y extends core::String = core::String>(self::D<Y>, self::D<core::String>?) → void
-  return <Y extends core::String = core::String>(self::D<Y> a, self::D<core::String>? b) → void => self::Extension1|method2<self::Extension1|get#method2::X%, Y>(#this, a, b);
+static method Extension1|get#method2<X extends self::A<self::Extension1|get#method2::X%>? = self::A<dynamic>?>(lowered final self::A<self::Extension1|get#method2::X%> #this) → <Y extends core::String>(self::D<Y>, self::D<core::String>?) → void
+  return <Y extends core::String>(self::D<Y> a, self::D<core::String>? b) → void => self::Extension1|method2<self::Extension1|get#method2::X%, Y>(#this, a, b);
 static method test() → dynamic {
   self::A<Null> a = new self::A::•<Null>();
 }
diff --git a/pkg/front_end/testcases/nnbd/issue43211.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/issue43211.dart.weak.outline.expect
index 02689e0..aef5c33 100644
--- a/pkg/front_end/testcases/nnbd/issue43211.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/issue43211.dart.weak.outline.expect
@@ -108,16 +108,16 @@
   synthetic constructor •() → self::A<self::A::X%>
     ;
 }
-class D<X extends core::num = core::num> extends core::Object {
+class D<X extends core::num> extends core::Object {
   synthetic constructor •() → self::D<self::D::X>
     ;
 }
-class B<X extends self::A<Null>? = self::A<Null>?> extends core::Object implements self::A<self::B::X%> {
+class B<X extends self::A<Null>?> extends core::Object implements self::A<self::B::X%> {
   synthetic constructor •() → self::B<self::B::X%>
     ;
-  method method1<Y extends self::A<Null>? = self::A<Null>?>(self::A<self::B::method1::Y%> a, self::A<self::A<Null>>? b) → void
+  method method1<Y extends self::A<Null>?>(self::A<self::B::method1::Y%> a, self::A<self::A<Null>>? b) → void
     ;
-  method method2<Y extends core::String = core::String>(self::D<self::B::method2::Y> a, self::D<core::String>? b) → void
+  method method2<Y extends core::String>(self::D<self::B::method2::Y> a, self::D<core::String>? b) → void
     ;
 }
 class C extends core::Object {
@@ -135,16 +135,16 @@
   method method2 = self::Extension1|method2;
   tearoff method2 = self::Extension1|get#method2;
 }
-extension ext2<X extends self::A<Null>? = self::A<Null>?> on self::A<X%> {
+extension ext2<X extends self::A<Null>?> on self::A<X%> {
 }
 static method Extension1|method1<X extends self::A<self::Extension1|method1::X%>? = self::A<dynamic>?, Y extends self::A<self::Extension1|method1::Y%>? = self::A<dynamic>?>(lowered final self::A<self::Extension1|method1::X%> #this, self::A<self::Extension1|method1::Y%> a, self::A<self::A<Null>>? b) → void
   ;
 static method Extension1|get#method1<X extends self::A<self::Extension1|get#method1::X%>? = self::A<dynamic>?>(lowered final self::A<self::Extension1|get#method1::X%> #this) → <Y extends self::A<Y%>? = self::A<dynamic>?>(self::A<Y%>, self::A<self::A<Null>>?) → void
   return <Y extends self::A<Y%>? = self::A<dynamic>?>(self::A<Y%> a, self::A<self::A<Null>>? b) → void => self::Extension1|method1<self::Extension1|get#method1::X%, Y%>(#this, a, b);
-static method Extension1|method2<X extends self::A<self::Extension1|method2::X%>? = self::A<dynamic>?, Y extends core::String = core::String>(lowered final self::A<self::Extension1|method2::X%> #this, self::D<self::Extension1|method2::Y> a, self::D<core::String>? b) → void
+static method Extension1|method2<X extends self::A<self::Extension1|method2::X%>? = self::A<dynamic>?, Y extends core::String>(lowered final self::A<self::Extension1|method2::X%> #this, self::D<self::Extension1|method2::Y> a, self::D<core::String>? b) → void
   ;
-static method Extension1|get#method2<X extends self::A<self::Extension1|get#method2::X%>? = self::A<dynamic>?>(lowered final self::A<self::Extension1|get#method2::X%> #this) → <Y extends core::String = core::String>(self::D<Y>, self::D<core::String>?) → void
-  return <Y extends core::String = core::String>(self::D<Y> a, self::D<core::String>? b) → void => self::Extension1|method2<self::Extension1|get#method2::X%, Y>(#this, a, b);
+static method Extension1|get#method2<X extends self::A<self::Extension1|get#method2::X%>? = self::A<dynamic>?>(lowered final self::A<self::Extension1|get#method2::X%> #this) → <Y extends core::String>(self::D<Y>, self::D<core::String>?) → void
+  return <Y extends core::String>(self::D<Y> a, self::D<core::String>? b) → void => self::Extension1|method2<self::Extension1|get#method2::X%, Y>(#this, a, b);
 static method test() → dynamic
   ;
 static method main() → dynamic
diff --git a/pkg/front_end/testcases/nnbd/issue43211.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/issue43211.dart.weak.transformed.expect
index 0fcf8ea..48a5a0a 100644
--- a/pkg/front_end/testcases/nnbd/issue43211.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue43211.dart.weak.transformed.expect
@@ -202,20 +202,20 @@
     : super core::Object::•()
     ;
 }
-class D<X extends core::num = core::num> extends core::Object {
+class D<X extends core::num> extends core::Object {
   synthetic constructor •() → self::D<self::D::X>
     : super core::Object::•()
     ;
 }
-class B<X extends self::A<Null>? = self::A<Null>?> extends core::Object implements self::A<self::B::X%> {
+class B<X extends self::A<Null>?> extends core::Object implements self::A<self::B::X%> {
   synthetic constructor •() → self::B<self::B::X%>
     : super core::Object::•()
     ;
-  method method1<Y extends self::A<Null>? = self::A<Null>?>(self::A<self::B::method1::Y%> a, self::A<self::A<Null>>? b) → void {
+  method method1<Y extends self::A<Null>?>(self::A<self::B::method1::Y%> a, self::A<self::A<Null>>? b) → void {
     self::A<self::B::method1::Y%>? c;
     self::A<self::A<Null>>? d;
   }
-  method method2<Y extends core::String = core::String>(self::D<self::B::method2::Y> a, self::D<core::String>? b) → void {
+  method method2<Y extends core::String>(self::D<self::B::method2::Y> a, self::D<core::String>? b) → void {
     self::D<self::B::method2::Y>? c;
     self::D<core::String>? d;
   }
@@ -241,7 +241,7 @@
   method method2 = self::Extension1|method2;
   tearoff method2 = self::Extension1|get#method2;
 }
-extension ext2<X extends self::A<Null>? = self::A<Null>?> on self::A<X%> {
+extension ext2<X extends self::A<Null>?> on self::A<X%> {
 }
 static method Extension1|method1<X extends self::A<self::Extension1|method1::X%>? = self::A<dynamic>?, Y extends self::A<self::Extension1|method1::Y%>? = self::A<dynamic>?>(lowered final self::A<self::Extension1|method1::X%> #this, self::A<self::Extension1|method1::Y%> a, self::A<self::A<Null>>? b) → void {
   self::A<self::Extension1|method1::Y%>? c;
@@ -249,12 +249,12 @@
 }
 static method Extension1|get#method1<X extends self::A<self::Extension1|get#method1::X%>? = self::A<dynamic>?>(lowered final self::A<self::Extension1|get#method1::X%> #this) → <Y extends self::A<Y%>? = self::A<dynamic>?>(self::A<Y%>, self::A<self::A<Null>>?) → void
   return <Y extends self::A<Y%>? = self::A<dynamic>?>(self::A<Y%> a, self::A<self::A<Null>>? b) → void => self::Extension1|method1<self::Extension1|get#method1::X%, Y%>(#this, a, b);
-static method Extension1|method2<X extends self::A<self::Extension1|method2::X%>? = self::A<dynamic>?, Y extends core::String = core::String>(lowered final self::A<self::Extension1|method2::X%> #this, self::D<self::Extension1|method2::Y> a, self::D<core::String>? b) → void {
+static method Extension1|method2<X extends self::A<self::Extension1|method2::X%>? = self::A<dynamic>?, Y extends core::String>(lowered final self::A<self::Extension1|method2::X%> #this, self::D<self::Extension1|method2::Y> a, self::D<core::String>? b) → void {
   self::D<self::Extension1|method2::Y>? c;
   self::D<core::String>? d;
 }
-static method Extension1|get#method2<X extends self::A<self::Extension1|get#method2::X%>? = self::A<dynamic>?>(lowered final self::A<self::Extension1|get#method2::X%> #this) → <Y extends core::String = core::String>(self::D<Y>, self::D<core::String>?) → void
-  return <Y extends core::String = core::String>(self::D<Y> a, self::D<core::String>? b) → void => self::Extension1|method2<self::Extension1|get#method2::X%, Y>(#this, a, b);
+static method Extension1|get#method2<X extends self::A<self::Extension1|get#method2::X%>? = self::A<dynamic>?>(lowered final self::A<self::Extension1|get#method2::X%> #this) → <Y extends core::String>(self::D<Y>, self::D<core::String>?) → void
+  return <Y extends core::String>(self::D<Y> a, self::D<core::String>? b) → void => self::Extension1|method2<self::Extension1|get#method2::X%, Y>(#this, a, b);
 static method test() → dynamic {
   self::A<Null> a = new self::A::•<Null>();
 }
diff --git a/pkg/front_end/testcases/nnbd/issue43256.dart.strong.expect b/pkg/front_end/testcases/nnbd/issue43256.dart.strong.expect
index 3c826d1..a77f5c0 100644
--- a/pkg/front_end/testcases/nnbd/issue43256.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/issue43256.dart.strong.expect
@@ -91,7 +91,7 @@
   if(self::i.{core::num::>}(0))
     #t5.{core::List::addAll}{Invariant}(self::nullableList!);
 } =>#t5;
-static method testMap<X extends dynamic = dynamic, Y extends core::Map<core::int, core::String>? = core::Map<core::int, core::String>?, Z extends core::Map<core::int, core::String> = core::Map<core::int, core::String>>(self::testMap::X% x, self::testMap::Y% y, self::testMap::Z z) → dynamic {
+static method testMap<X extends dynamic, Y extends core::Map<core::int, core::String>?, Z extends core::Map<core::int, core::String>>(self::testMap::X% x, self::testMap::Y% y, self::testMap::Z z) → dynamic {
   core::Map<dynamic, dynamic> map2 = block {
     final core::Map<dynamic, dynamic> #t6 = <dynamic, dynamic>{};
     if(self::i.{core::num::>}(0))
@@ -110,7 +110,7 @@
         #t6.{core::Map::[]=}{Invariant}(#t8.{core::MapEntry::key}, #t8.{core::MapEntry::value});
   } =>#t6;
 }
-static method testIterables<X extends dynamic = dynamic, Y extends core::List<core::int>? = core::List<core::int>?, Z extends core::List<core::int> = core::List<core::int>>(self::testIterables::X% x, self::testIterables::Y% y, self::testIterables::Z z) → dynamic {
+static method testIterables<X extends dynamic, Y extends core::List<core::int>?, Z extends core::List<core::int>>(self::testIterables::X% x, self::testIterables::Y% y, self::testIterables::Z z) → dynamic {
   core::Set<dynamic> set2 = block {
     final core::Set<dynamic> #t9 = col::LinkedHashSet::•<dynamic>();
     #t9.{core::Set::add}{Invariant}(0);
diff --git a/pkg/front_end/testcases/nnbd/issue43256.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/issue43256.dart.strong.transformed.expect
index afc253c..04e38068 100644
--- a/pkg/front_end/testcases/nnbd/issue43256.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue43256.dart.strong.transformed.expect
@@ -99,7 +99,7 @@
   if(self::i.{core::num::>}(0))
     #t5.{core::List::addAll}{Invariant}(self::nullableList!);
 } =>#t5;
-static method testMap<X extends dynamic = dynamic, Y extends core::Map<core::int, core::String>? = core::Map<core::int, core::String>?, Z extends core::Map<core::int, core::String> = core::Map<core::int, core::String>>(self::testMap::X% x, self::testMap::Y% y, self::testMap::Z z) → dynamic {
+static method testMap<X extends dynamic, Y extends core::Map<core::int, core::String>?, Z extends core::Map<core::int, core::String>>(self::testMap::X% x, self::testMap::Y% y, self::testMap::Z z) → dynamic {
   core::Map<dynamic, dynamic> map2 = block {
     final core::Map<dynamic, dynamic> #t6 = <dynamic, dynamic>{};
     if(self::i.{core::num::>}(0))
@@ -126,7 +126,7 @@
     }
   } =>#t6;
 }
-static method testIterables<X extends dynamic = dynamic, Y extends core::List<core::int>? = core::List<core::int>?, Z extends core::List<core::int> = core::List<core::int>>(self::testIterables::X% x, self::testIterables::Y% y, self::testIterables::Z z) → dynamic {
+static method testIterables<X extends dynamic, Y extends core::List<core::int>?, Z extends core::List<core::int>>(self::testIterables::X% x, self::testIterables::Y% y, self::testIterables::Z z) → dynamic {
   core::Set<dynamic> set2 = block {
     final core::Set<dynamic> #t9 = new col::_CompactLinkedHashSet::•<dynamic>();
     #t9.{core::Set::add}{Invariant}(0);
diff --git a/pkg/front_end/testcases/nnbd/issue43256.dart.weak.expect b/pkg/front_end/testcases/nnbd/issue43256.dart.weak.expect
index 3c826d1..a77f5c0 100644
--- a/pkg/front_end/testcases/nnbd/issue43256.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/issue43256.dart.weak.expect
@@ -91,7 +91,7 @@
   if(self::i.{core::num::>}(0))
     #t5.{core::List::addAll}{Invariant}(self::nullableList!);
 } =>#t5;
-static method testMap<X extends dynamic = dynamic, Y extends core::Map<core::int, core::String>? = core::Map<core::int, core::String>?, Z extends core::Map<core::int, core::String> = core::Map<core::int, core::String>>(self::testMap::X% x, self::testMap::Y% y, self::testMap::Z z) → dynamic {
+static method testMap<X extends dynamic, Y extends core::Map<core::int, core::String>?, Z extends core::Map<core::int, core::String>>(self::testMap::X% x, self::testMap::Y% y, self::testMap::Z z) → dynamic {
   core::Map<dynamic, dynamic> map2 = block {
     final core::Map<dynamic, dynamic> #t6 = <dynamic, dynamic>{};
     if(self::i.{core::num::>}(0))
@@ -110,7 +110,7 @@
         #t6.{core::Map::[]=}{Invariant}(#t8.{core::MapEntry::key}, #t8.{core::MapEntry::value});
   } =>#t6;
 }
-static method testIterables<X extends dynamic = dynamic, Y extends core::List<core::int>? = core::List<core::int>?, Z extends core::List<core::int> = core::List<core::int>>(self::testIterables::X% x, self::testIterables::Y% y, self::testIterables::Z z) → dynamic {
+static method testIterables<X extends dynamic, Y extends core::List<core::int>?, Z extends core::List<core::int>>(self::testIterables::X% x, self::testIterables::Y% y, self::testIterables::Z z) → dynamic {
   core::Set<dynamic> set2 = block {
     final core::Set<dynamic> #t9 = col::LinkedHashSet::•<dynamic>();
     #t9.{core::Set::add}{Invariant}(0);
diff --git a/pkg/front_end/testcases/nnbd/issue43256.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/issue43256.dart.weak.outline.expect
index d008a19..ef444c5 100644
--- a/pkg/front_end/testcases/nnbd/issue43256.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/issue43256.dart.weak.outline.expect
@@ -10,9 +10,9 @@
 static field core::Map<dynamic, dynamic> map1;
 static field core::Set<dynamic> set1;
 static field core::List<dynamic> list1;
-static method testMap<X extends dynamic = dynamic, Y extends core::Map<core::int, core::String>? = core::Map<core::int, core::String>?, Z extends core::Map<core::int, core::String> = core::Map<core::int, core::String>>(self::testMap::X% x, self::testMap::Y% y, self::testMap::Z z) → dynamic
+static method testMap<X extends dynamic, Y extends core::Map<core::int, core::String>?, Z extends core::Map<core::int, core::String>>(self::testMap::X% x, self::testMap::Y% y, self::testMap::Z z) → dynamic
   ;
-static method testIterables<X extends dynamic = dynamic, Y extends core::List<core::int>? = core::List<core::int>?, Z extends core::List<core::int> = core::List<core::int>>(self::testIterables::X% x, self::testIterables::Y% y, self::testIterables::Z z) → dynamic
+static method testIterables<X extends dynamic, Y extends core::List<core::int>?, Z extends core::List<core::int>>(self::testIterables::X% x, self::testIterables::Y% y, self::testIterables::Z z) → dynamic
   ;
 static method main() → dynamic
   ;
diff --git a/pkg/front_end/testcases/nnbd/issue43256.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/issue43256.dart.weak.transformed.expect
index afc253c..04e38068 100644
--- a/pkg/front_end/testcases/nnbd/issue43256.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue43256.dart.weak.transformed.expect
@@ -99,7 +99,7 @@
   if(self::i.{core::num::>}(0))
     #t5.{core::List::addAll}{Invariant}(self::nullableList!);
 } =>#t5;
-static method testMap<X extends dynamic = dynamic, Y extends core::Map<core::int, core::String>? = core::Map<core::int, core::String>?, Z extends core::Map<core::int, core::String> = core::Map<core::int, core::String>>(self::testMap::X% x, self::testMap::Y% y, self::testMap::Z z) → dynamic {
+static method testMap<X extends dynamic, Y extends core::Map<core::int, core::String>?, Z extends core::Map<core::int, core::String>>(self::testMap::X% x, self::testMap::Y% y, self::testMap::Z z) → dynamic {
   core::Map<dynamic, dynamic> map2 = block {
     final core::Map<dynamic, dynamic> #t6 = <dynamic, dynamic>{};
     if(self::i.{core::num::>}(0))
@@ -126,7 +126,7 @@
     }
   } =>#t6;
 }
-static method testIterables<X extends dynamic = dynamic, Y extends core::List<core::int>? = core::List<core::int>?, Z extends core::List<core::int> = core::List<core::int>>(self::testIterables::X% x, self::testIterables::Y% y, self::testIterables::Z z) → dynamic {
+static method testIterables<X extends dynamic, Y extends core::List<core::int>?, Z extends core::List<core::int>>(self::testIterables::X% x, self::testIterables::Y% y, self::testIterables::Z z) → dynamic {
   core::Set<dynamic> set2 = block {
     final core::Set<dynamic> #t9 = new col::_CompactLinkedHashSet::•<dynamic>();
     #t9.{core::Set::add}{Invariant}(0);
diff --git a/pkg/front_end/testcases/nnbd/issue43278.dart.strong.expect b/pkg/front_end/testcases/nnbd/issue43278.dart.strong.expect
index 3bfcc52..cd83b1e 100644
--- a/pkg/front_end/testcases/nnbd/issue43278.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/issue43278.dart.strong.expect
@@ -44,7 +44,7 @@
   get barExtension = self::Extension|get#barExtension;
   set fooExtension = self::Extension|set#fooExtension;
 }
-static method test<T extends self::A? = self::A?>(self::A? a, self::test::T% t, dynamic d, core::int x) → dynamic {
+static method test<T extends self::A?>(self::A? a, self::test::T% t, dynamic d, core::int x) → dynamic {
   let final self::A? #t1 = a in (let final Never #t2 = invalid-expression "pkg/front_end/testcases/nnbd/issue43278.dart:13:5: Error: Property 'foo' cannot be accessed on 'A?' because it is potentially null.
  - 'A' is from 'pkg/front_end/testcases/nnbd/issue43278.dart'.
 Try accessing using ?. instead.
@@ -69,7 +69,7 @@
 static method Extension|set#fooExtension(lowered final self::B #this, core::int? value) → void {}
 static method Extension|get#barExtension(lowered final self::B #this) → self::B
   return new self::B::•();
-static method testExtension<T extends self::B? = self::B?>(self::B? b, self::testExtension::T% t, core::int x) → dynamic {
+static method testExtension<T extends self::B?>(self::B? b, self::testExtension::T% t, core::int x) → dynamic {
   let final self::B? #t10 = b in (let final Never #t11 = invalid-expression "pkg/front_end/testcases/nnbd/issue43278.dart:28:5: Error: Property 'fooExtension' cannot be accessed on 'B?' because it is potentially null.
  - 'B' is from 'pkg/front_end/testcases/nnbd/issue43278.dart'.
 Try accessing using ?. instead.
diff --git a/pkg/front_end/testcases/nnbd/issue43278.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/issue43278.dart.strong.transformed.expect
index 3bfcc52..cd83b1e 100644
--- a/pkg/front_end/testcases/nnbd/issue43278.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue43278.dart.strong.transformed.expect
@@ -44,7 +44,7 @@
   get barExtension = self::Extension|get#barExtension;
   set fooExtension = self::Extension|set#fooExtension;
 }
-static method test<T extends self::A? = self::A?>(self::A? a, self::test::T% t, dynamic d, core::int x) → dynamic {
+static method test<T extends self::A?>(self::A? a, self::test::T% t, dynamic d, core::int x) → dynamic {
   let final self::A? #t1 = a in (let final Never #t2 = invalid-expression "pkg/front_end/testcases/nnbd/issue43278.dart:13:5: Error: Property 'foo' cannot be accessed on 'A?' because it is potentially null.
  - 'A' is from 'pkg/front_end/testcases/nnbd/issue43278.dart'.
 Try accessing using ?. instead.
@@ -69,7 +69,7 @@
 static method Extension|set#fooExtension(lowered final self::B #this, core::int? value) → void {}
 static method Extension|get#barExtension(lowered final self::B #this) → self::B
   return new self::B::•();
-static method testExtension<T extends self::B? = self::B?>(self::B? b, self::testExtension::T% t, core::int x) → dynamic {
+static method testExtension<T extends self::B?>(self::B? b, self::testExtension::T% t, core::int x) → dynamic {
   let final self::B? #t10 = b in (let final Never #t11 = invalid-expression "pkg/front_end/testcases/nnbd/issue43278.dart:28:5: Error: Property 'fooExtension' cannot be accessed on 'B?' because it is potentially null.
  - 'B' is from 'pkg/front_end/testcases/nnbd/issue43278.dart'.
 Try accessing using ?. instead.
diff --git a/pkg/front_end/testcases/nnbd/issue43278.dart.weak.expect b/pkg/front_end/testcases/nnbd/issue43278.dart.weak.expect
index 3bfcc52..cd83b1e 100644
--- a/pkg/front_end/testcases/nnbd/issue43278.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/issue43278.dart.weak.expect
@@ -44,7 +44,7 @@
   get barExtension = self::Extension|get#barExtension;
   set fooExtension = self::Extension|set#fooExtension;
 }
-static method test<T extends self::A? = self::A?>(self::A? a, self::test::T% t, dynamic d, core::int x) → dynamic {
+static method test<T extends self::A?>(self::A? a, self::test::T% t, dynamic d, core::int x) → dynamic {
   let final self::A? #t1 = a in (let final Never #t2 = invalid-expression "pkg/front_end/testcases/nnbd/issue43278.dart:13:5: Error: Property 'foo' cannot be accessed on 'A?' because it is potentially null.
  - 'A' is from 'pkg/front_end/testcases/nnbd/issue43278.dart'.
 Try accessing using ?. instead.
@@ -69,7 +69,7 @@
 static method Extension|set#fooExtension(lowered final self::B #this, core::int? value) → void {}
 static method Extension|get#barExtension(lowered final self::B #this) → self::B
   return new self::B::•();
-static method testExtension<T extends self::B? = self::B?>(self::B? b, self::testExtension::T% t, core::int x) → dynamic {
+static method testExtension<T extends self::B?>(self::B? b, self::testExtension::T% t, core::int x) → dynamic {
   let final self::B? #t10 = b in (let final Never #t11 = invalid-expression "pkg/front_end/testcases/nnbd/issue43278.dart:28:5: Error: Property 'fooExtension' cannot be accessed on 'B?' because it is potentially null.
  - 'B' is from 'pkg/front_end/testcases/nnbd/issue43278.dart'.
 Try accessing using ?. instead.
diff --git a/pkg/front_end/testcases/nnbd/issue43278.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/issue43278.dart.weak.outline.expect
index 795331a..cb81d1f 100644
--- a/pkg/front_end/testcases/nnbd/issue43278.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/issue43278.dart.weak.outline.expect
@@ -17,7 +17,7 @@
   get barExtension = self::Extension|get#barExtension;
   set fooExtension = self::Extension|set#fooExtension;
 }
-static method test<T extends self::A? = self::A?>(self::A? a, self::test::T% t, dynamic d, core::int x) → dynamic
+static method test<T extends self::A?>(self::A? a, self::test::T% t, dynamic d, core::int x) → dynamic
   ;
 static method Extension|get#fooExtension(lowered final self::B #this) → core::int?
   ;
@@ -25,7 +25,7 @@
   ;
 static method Extension|get#barExtension(lowered final self::B #this) → self::B
   ;
-static method testExtension<T extends self::B? = self::B?>(self::B? b, self::testExtension::T% t, core::int x) → dynamic
+static method testExtension<T extends self::B?>(self::B? b, self::testExtension::T% t, core::int x) → dynamic
   ;
 static method main() → dynamic
   ;
diff --git a/pkg/front_end/testcases/nnbd/issue43278.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/issue43278.dart.weak.transformed.expect
index 3bfcc52..cd83b1e 100644
--- a/pkg/front_end/testcases/nnbd/issue43278.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue43278.dart.weak.transformed.expect
@@ -44,7 +44,7 @@
   get barExtension = self::Extension|get#barExtension;
   set fooExtension = self::Extension|set#fooExtension;
 }
-static method test<T extends self::A? = self::A?>(self::A? a, self::test::T% t, dynamic d, core::int x) → dynamic {
+static method test<T extends self::A?>(self::A? a, self::test::T% t, dynamic d, core::int x) → dynamic {
   let final self::A? #t1 = a in (let final Never #t2 = invalid-expression "pkg/front_end/testcases/nnbd/issue43278.dart:13:5: Error: Property 'foo' cannot be accessed on 'A?' because it is potentially null.
  - 'A' is from 'pkg/front_end/testcases/nnbd/issue43278.dart'.
 Try accessing using ?. instead.
@@ -69,7 +69,7 @@
 static method Extension|set#fooExtension(lowered final self::B #this, core::int? value) → void {}
 static method Extension|get#barExtension(lowered final self::B #this) → self::B
   return new self::B::•();
-static method testExtension<T extends self::B? = self::B?>(self::B? b, self::testExtension::T% t, core::int x) → dynamic {
+static method testExtension<T extends self::B?>(self::B? b, self::testExtension::T% t, core::int x) → dynamic {
   let final self::B? #t10 = b in (let final Never #t11 = invalid-expression "pkg/front_end/testcases/nnbd/issue43278.dart:28:5: Error: Property 'fooExtension' cannot be accessed on 'B?' because it is potentially null.
  - 'B' is from 'pkg/front_end/testcases/nnbd/issue43278.dart'.
 Try accessing using ?. instead.
diff --git a/pkg/front_end/testcases/nnbd/issue43455.dart.strong.expect b/pkg/front_end/testcases/nnbd/issue43455.dart.strong.expect
index e6ba91c..9a0b8b5 100644
--- a/pkg/front_end/testcases/nnbd/issue43455.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/issue43455.dart.strong.expect
@@ -3,7 +3,7 @@
 import "dart:core" as core;
 import "dart:collection" as col;
 
-class C<X extends core::Object? = core::Object?, Y extends core::Object = core::Object> extends core::Object {
+class C<X extends core::Object?, Y extends core::Object> extends core::Object {
   synthetic constructor •() → self::C<self::C::X%, self::C::Y>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nnbd/issue43455.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/issue43455.dart.strong.transformed.expect
index 47bd5a2..ceddbed 100644
--- a/pkg/front_end/testcases/nnbd/issue43455.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue43455.dart.strong.transformed.expect
@@ -3,7 +3,7 @@
 import "dart:core" as core;
 import "dart:collection" as col;
 
-class C<X extends core::Object? = core::Object?, Y extends core::Object = core::Object> extends core::Object {
+class C<X extends core::Object?, Y extends core::Object> extends core::Object {
   synthetic constructor •() → self::C<self::C::X%, self::C::Y>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nnbd/issue43455.dart.weak.expect b/pkg/front_end/testcases/nnbd/issue43455.dart.weak.expect
index e6ba91c..9a0b8b5 100644
--- a/pkg/front_end/testcases/nnbd/issue43455.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/issue43455.dart.weak.expect
@@ -3,7 +3,7 @@
 import "dart:core" as core;
 import "dart:collection" as col;
 
-class C<X extends core::Object? = core::Object?, Y extends core::Object = core::Object> extends core::Object {
+class C<X extends core::Object?, Y extends core::Object> extends core::Object {
   synthetic constructor •() → self::C<self::C::X%, self::C::Y>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nnbd/issue43455.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/issue43455.dart.weak.outline.expect
index d9fa31c..dfdf23f 100644
--- a/pkg/front_end/testcases/nnbd/issue43455.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/issue43455.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class C<X extends core::Object? = core::Object?, Y extends core::Object = core::Object> extends core::Object {
+class C<X extends core::Object?, Y extends core::Object> extends core::Object {
   synthetic constructor •() → self::C<self::C::X%, self::C::Y>
     ;
   method test(generic-covariant-impl self::C::X% x, generic-covariant-impl self::C::Y? y) → dynamic
diff --git a/pkg/front_end/testcases/nnbd/issue43455.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/issue43455.dart.weak.transformed.expect
index 47bd5a2..ceddbed 100644
--- a/pkg/front_end/testcases/nnbd/issue43455.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue43455.dart.weak.transformed.expect
@@ -3,7 +3,7 @@
 import "dart:core" as core;
 import "dart:collection" as col;
 
-class C<X extends core::Object? = core::Object?, Y extends core::Object = core::Object> extends core::Object {
+class C<X extends core::Object?, Y extends core::Object> extends core::Object {
   synthetic constructor •() → self::C<self::C::X%, self::C::Y>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nnbd/issue43495.dart.strong.expect b/pkg/front_end/testcases/nnbd/issue43495.dart.strong.expect
index 0934075..e5985d6 100644
--- a/pkg/front_end/testcases/nnbd/issue43495.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/issue43495.dart.strong.expect
@@ -449,7 +449,7 @@
     }
   } =>#t98];
 }
-static method bar<X extends core::List<core::int>? = core::List<core::int>?, Y extends core::Set<core::int>? = core::Set<core::int>?, Z extends core::Iterable<core::int>? = core::Iterable<core::int>?, W extends core::Map<core::int, core::int>? = core::Map<core::int, core::int>?>(core::bool condition, core::Iterable<dynamic> iterable, self::bar::X% x, self::bar::Y% y, self::bar::Z% z, self::bar::W% w) → dynamic {
+static method bar<X extends core::List<core::int>?, Y extends core::Set<core::int>?, Z extends core::Iterable<core::int>?, W extends core::Map<core::int, core::int>?>(core::bool condition, core::Iterable<dynamic> iterable, self::bar::X% x, self::bar::Y% y, self::bar::Z% z, self::bar::W% w) → dynamic {
   return <core::Object>[ block {
     final core::Set<core::int> #t101 = col::LinkedHashSet::•<core::int>();
     for (final dynamic #t102 in invalid-expression "pkg/front_end/testcases/nnbd/issue43495.dart:50:9: Error: An expression whose value can be 'null' must be null-checked before it can be dereferenced.
diff --git a/pkg/front_end/testcases/nnbd/issue43495.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/issue43495.dart.strong.transformed.expect
index 3162d81..7d89db1 100644
--- a/pkg/front_end/testcases/nnbd/issue43495.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue43495.dart.strong.transformed.expect
@@ -635,7 +635,7 @@
     }
   } =>#t98];
 }
-static method bar<X extends core::List<core::int>? = core::List<core::int>?, Y extends core::Set<core::int>? = core::Set<core::int>?, Z extends core::Iterable<core::int>? = core::Iterable<core::int>?, W extends core::Map<core::int, core::int>? = core::Map<core::int, core::int>?>(core::bool condition, core::Iterable<dynamic> iterable, self::bar::X% x, self::bar::Y% y, self::bar::Z% z, self::bar::W% w) → dynamic {
+static method bar<X extends core::List<core::int>?, Y extends core::Set<core::int>?, Z extends core::Iterable<core::int>?, W extends core::Map<core::int, core::int>?>(core::bool condition, core::Iterable<dynamic> iterable, self::bar::X% x, self::bar::Y% y, self::bar::Z% z, self::bar::W% w) → dynamic {
   return <core::Object>[ block {
     final core::Set<core::int> #t101 = new col::_CompactLinkedHashSet::•<core::int>();
     {
diff --git a/pkg/front_end/testcases/nnbd/issue43495.dart.weak.expect b/pkg/front_end/testcases/nnbd/issue43495.dart.weak.expect
index 0934075..e5985d6 100644
--- a/pkg/front_end/testcases/nnbd/issue43495.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/issue43495.dart.weak.expect
@@ -449,7 +449,7 @@
     }
   } =>#t98];
 }
-static method bar<X extends core::List<core::int>? = core::List<core::int>?, Y extends core::Set<core::int>? = core::Set<core::int>?, Z extends core::Iterable<core::int>? = core::Iterable<core::int>?, W extends core::Map<core::int, core::int>? = core::Map<core::int, core::int>?>(core::bool condition, core::Iterable<dynamic> iterable, self::bar::X% x, self::bar::Y% y, self::bar::Z% z, self::bar::W% w) → dynamic {
+static method bar<X extends core::List<core::int>?, Y extends core::Set<core::int>?, Z extends core::Iterable<core::int>?, W extends core::Map<core::int, core::int>?>(core::bool condition, core::Iterable<dynamic> iterable, self::bar::X% x, self::bar::Y% y, self::bar::Z% z, self::bar::W% w) → dynamic {
   return <core::Object>[ block {
     final core::Set<core::int> #t101 = col::LinkedHashSet::•<core::int>();
     for (final dynamic #t102 in invalid-expression "pkg/front_end/testcases/nnbd/issue43495.dart:50:9: Error: An expression whose value can be 'null' must be null-checked before it can be dereferenced.
diff --git a/pkg/front_end/testcases/nnbd/issue43495.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/issue43495.dart.weak.outline.expect
index 89dfdbb..3389234 100644
--- a/pkg/front_end/testcases/nnbd/issue43495.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/issue43495.dart.weak.outline.expect
@@ -4,7 +4,7 @@
 
 static method foo(core::bool condition, core::Iterable<dynamic> iterable, core::List<core::int>? a, core::Set<core::int>? b, core::Iterable<core::int>? c, core::Map<core::int, core::int>? d) → dynamic
   ;
-static method bar<X extends core::List<core::int>? = core::List<core::int>?, Y extends core::Set<core::int>? = core::Set<core::int>?, Z extends core::Iterable<core::int>? = core::Iterable<core::int>?, W extends core::Map<core::int, core::int>? = core::Map<core::int, core::int>?>(core::bool condition, core::Iterable<dynamic> iterable, self::bar::X% x, self::bar::Y% y, self::bar::Z% z, self::bar::W% w) → dynamic
+static method bar<X extends core::List<core::int>?, Y extends core::Set<core::int>?, Z extends core::Iterable<core::int>?, W extends core::Map<core::int, core::int>?>(core::bool condition, core::Iterable<dynamic> iterable, self::bar::X% x, self::bar::Y% y, self::bar::Z% z, self::bar::W% w) → dynamic
   ;
 static method main() → dynamic
   ;
diff --git a/pkg/front_end/testcases/nnbd/issue43495.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/issue43495.dart.weak.transformed.expect
index 3162d81..7d89db1 100644
--- a/pkg/front_end/testcases/nnbd/issue43495.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue43495.dart.weak.transformed.expect
@@ -635,7 +635,7 @@
     }
   } =>#t98];
 }
-static method bar<X extends core::List<core::int>? = core::List<core::int>?, Y extends core::Set<core::int>? = core::Set<core::int>?, Z extends core::Iterable<core::int>? = core::Iterable<core::int>?, W extends core::Map<core::int, core::int>? = core::Map<core::int, core::int>?>(core::bool condition, core::Iterable<dynamic> iterable, self::bar::X% x, self::bar::Y% y, self::bar::Z% z, self::bar::W% w) → dynamic {
+static method bar<X extends core::List<core::int>?, Y extends core::Set<core::int>?, Z extends core::Iterable<core::int>?, W extends core::Map<core::int, core::int>?>(core::bool condition, core::Iterable<dynamic> iterable, self::bar::X% x, self::bar::Y% y, self::bar::Z% z, self::bar::W% w) → dynamic {
   return <core::Object>[ block {
     final core::Set<core::int> #t101 = new col::_CompactLinkedHashSet::•<core::int>();
     {
diff --git a/pkg/front_end/testcases/nnbd/issue43536.dart.strong.expect b/pkg/front_end/testcases/nnbd/issue43536.dart.strong.expect
index e22d4b0..de6fdb8 100644
--- a/pkg/front_end/testcases/nnbd/issue43536.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/issue43536.dart.strong.expect
@@ -6,10 +6,10 @@
   synthetic constructor •() → self::C<self::C::T%>
     : super core::Object::•()
     ;
-  method foo<generic-covariant-impl E extends self::C::T% = self::C::T%>(core::List<self::C::foo::E%> list) → dynamic {
+  method foo<generic-covariant-impl E extends self::C::T%>(core::List<self::C::foo::E%> list) → dynamic {
     core::List<self::C::foo::E%> variable = this.{self::C::method}<self::C::foo::E%>(list);
   }
-  method method<generic-covariant-impl F extends self::C::T% = self::C::T%>(core::List<self::C::method::F%> list) → core::List<self::C::method::F%>
+  method method<generic-covariant-impl F extends self::C::T%>(core::List<self::C::method::F%> list) → core::List<self::C::method::F%>
     return list;
 }
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd/issue43536.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/issue43536.dart.strong.transformed.expect
index e22d4b0..de6fdb8 100644
--- a/pkg/front_end/testcases/nnbd/issue43536.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue43536.dart.strong.transformed.expect
@@ -6,10 +6,10 @@
   synthetic constructor •() → self::C<self::C::T%>
     : super core::Object::•()
     ;
-  method foo<generic-covariant-impl E extends self::C::T% = self::C::T%>(core::List<self::C::foo::E%> list) → dynamic {
+  method foo<generic-covariant-impl E extends self::C::T%>(core::List<self::C::foo::E%> list) → dynamic {
     core::List<self::C::foo::E%> variable = this.{self::C::method}<self::C::foo::E%>(list);
   }
-  method method<generic-covariant-impl F extends self::C::T% = self::C::T%>(core::List<self::C::method::F%> list) → core::List<self::C::method::F%>
+  method method<generic-covariant-impl F extends self::C::T%>(core::List<self::C::method::F%> list) → core::List<self::C::method::F%>
     return list;
 }
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd/issue43536.dart.weak.expect b/pkg/front_end/testcases/nnbd/issue43536.dart.weak.expect
index e22d4b0..de6fdb8 100644
--- a/pkg/front_end/testcases/nnbd/issue43536.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/issue43536.dart.weak.expect
@@ -6,10 +6,10 @@
   synthetic constructor •() → self::C<self::C::T%>
     : super core::Object::•()
     ;
-  method foo<generic-covariant-impl E extends self::C::T% = self::C::T%>(core::List<self::C::foo::E%> list) → dynamic {
+  method foo<generic-covariant-impl E extends self::C::T%>(core::List<self::C::foo::E%> list) → dynamic {
     core::List<self::C::foo::E%> variable = this.{self::C::method}<self::C::foo::E%>(list);
   }
-  method method<generic-covariant-impl F extends self::C::T% = self::C::T%>(core::List<self::C::method::F%> list) → core::List<self::C::method::F%>
+  method method<generic-covariant-impl F extends self::C::T%>(core::List<self::C::method::F%> list) → core::List<self::C::method::F%>
     return list;
 }
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd/issue43536.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/issue43536.dart.weak.outline.expect
index 15e7e74..db3198e 100644
--- a/pkg/front_end/testcases/nnbd/issue43536.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/issue43536.dart.weak.outline.expect
@@ -5,9 +5,9 @@
 class C<T extends core::Object? = dynamic> extends core::Object {
   synthetic constructor •() → self::C<self::C::T%>
     ;
-  method foo<generic-covariant-impl E extends self::C::T% = self::C::T%>(core::List<self::C::foo::E%> list) → dynamic
+  method foo<generic-covariant-impl E extends self::C::T%>(core::List<self::C::foo::E%> list) → dynamic
     ;
-  method method<generic-covariant-impl F extends self::C::T% = self::C::T%>(core::List<self::C::method::F%> list) → core::List<self::C::method::F%>
+  method method<generic-covariant-impl F extends self::C::T%>(core::List<self::C::method::F%> list) → core::List<self::C::method::F%>
     ;
 }
 static method main() → dynamic
diff --git a/pkg/front_end/testcases/nnbd/issue43536.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/issue43536.dart.weak.transformed.expect
index e22d4b0..de6fdb8 100644
--- a/pkg/front_end/testcases/nnbd/issue43536.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue43536.dart.weak.transformed.expect
@@ -6,10 +6,10 @@
   synthetic constructor •() → self::C<self::C::T%>
     : super core::Object::•()
     ;
-  method foo<generic-covariant-impl E extends self::C::T% = self::C::T%>(core::List<self::C::foo::E%> list) → dynamic {
+  method foo<generic-covariant-impl E extends self::C::T%>(core::List<self::C::foo::E%> list) → dynamic {
     core::List<self::C::foo::E%> variable = this.{self::C::method}<self::C::foo::E%>(list);
   }
-  method method<generic-covariant-impl F extends self::C::T% = self::C::T%>(core::List<self::C::method::F%> list) → core::List<self::C::method::F%>
+  method method<generic-covariant-impl F extends self::C::T%>(core::List<self::C::method::F%> list) → core::List<self::C::method::F%>
     return list;
 }
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd/issue43591.dart.strong.expect b/pkg/front_end/testcases/nnbd/issue43591.dart.strong.expect
index d9bdceb..c09bec5 100644
--- a/pkg/front_end/testcases/nnbd/issue43591.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/issue43591.dart.strong.expect
@@ -10,7 +10,7 @@
 static method method1<S extends core::Object? = dynamic>(self::method1::S% s) → dynamic {
   (self::method1::S%) → self::method1::S% f = self::E|get#f<self::method1::S%>(s);
 }
-static method method2<S extends dynamic = dynamic>(self::method2::S% s) → dynamic {
+static method method2<S extends dynamic>(self::method2::S% s) → dynamic {
   self::throws(() → void => s.f);
 }
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd/issue43591.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/issue43591.dart.strong.transformed.expect
index d9bdceb..c09bec5 100644
--- a/pkg/front_end/testcases/nnbd/issue43591.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue43591.dart.strong.transformed.expect
@@ -10,7 +10,7 @@
 static method method1<S extends core::Object? = dynamic>(self::method1::S% s) → dynamic {
   (self::method1::S%) → self::method1::S% f = self::E|get#f<self::method1::S%>(s);
 }
-static method method2<S extends dynamic = dynamic>(self::method2::S% s) → dynamic {
+static method method2<S extends dynamic>(self::method2::S% s) → dynamic {
   self::throws(() → void => s.f);
 }
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd/issue43591.dart.weak.expect b/pkg/front_end/testcases/nnbd/issue43591.dart.weak.expect
index d9bdceb..c09bec5 100644
--- a/pkg/front_end/testcases/nnbd/issue43591.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/issue43591.dart.weak.expect
@@ -10,7 +10,7 @@
 static method method1<S extends core::Object? = dynamic>(self::method1::S% s) → dynamic {
   (self::method1::S%) → self::method1::S% f = self::E|get#f<self::method1::S%>(s);
 }
-static method method2<S extends dynamic = dynamic>(self::method2::S% s) → dynamic {
+static method method2<S extends dynamic>(self::method2::S% s) → dynamic {
   self::throws(() → void => s.f);
 }
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd/issue43591.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/issue43591.dart.weak.outline.expect
index f3c723d..9128f85 100644
--- a/pkg/front_end/testcases/nnbd/issue43591.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/issue43591.dart.weak.outline.expect
@@ -9,7 +9,7 @@
   ;
 static method method1<S extends core::Object? = dynamic>(self::method1::S% s) → dynamic
   ;
-static method method2<S extends dynamic = dynamic>(self::method2::S% s) → dynamic
+static method method2<S extends dynamic>(self::method2::S% s) → dynamic
   ;
 static method main() → dynamic
   ;
diff --git a/pkg/front_end/testcases/nnbd/issue43591.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/issue43591.dart.weak.transformed.expect
index d9bdceb..c09bec5 100644
--- a/pkg/front_end/testcases/nnbd/issue43591.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue43591.dart.weak.transformed.expect
@@ -10,7 +10,7 @@
 static method method1<S extends core::Object? = dynamic>(self::method1::S% s) → dynamic {
   (self::method1::S%) → self::method1::S% f = self::E|get#f<self::method1::S%>(s);
 }
-static method method2<S extends dynamic = dynamic>(self::method2::S% s) → dynamic {
+static method method2<S extends dynamic>(self::method2::S% s) → dynamic {
   self::throws(() → void => s.f);
 }
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd/issue44455.dart.strong.expect b/pkg/front_end/testcases/nnbd/issue44455.dart.strong.expect
index 2d1e9e6..d0065b3 100644
--- a/pkg/front_end/testcases/nnbd/issue44455.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/issue44455.dart.strong.expect
@@ -21,8 +21,8 @@
 import self as self;
 import "dart:core" as core;
 
-typedef F<Y extends core::num = core::num> = () → Y;
-typedef F2<Y extends core::num = core::num> = () → Y;
+typedef F<Y extends core::num> = () → Y;
+typedef F2<Y extends core::num> = () → Y;
 class A<X extends () → self::A::X = () → dynamic> extends core::Object {
   synthetic constructor •() → self::A<self::A::X>
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/nnbd/issue44455.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/issue44455.dart.strong.transformed.expect
index 2d1e9e6..d0065b3 100644
--- a/pkg/front_end/testcases/nnbd/issue44455.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue44455.dart.strong.transformed.expect
@@ -21,8 +21,8 @@
 import self as self;
 import "dart:core" as core;
 
-typedef F<Y extends core::num = core::num> = () → Y;
-typedef F2<Y extends core::num = core::num> = () → Y;
+typedef F<Y extends core::num> = () → Y;
+typedef F2<Y extends core::num> = () → Y;
 class A<X extends () → self::A::X = () → dynamic> extends core::Object {
   synthetic constructor •() → self::A<self::A::X>
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/nnbd/issue44455.dart.weak.expect b/pkg/front_end/testcases/nnbd/issue44455.dart.weak.expect
index 2d1e9e6..d0065b3 100644
--- a/pkg/front_end/testcases/nnbd/issue44455.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/issue44455.dart.weak.expect
@@ -21,8 +21,8 @@
 import self as self;
 import "dart:core" as core;
 
-typedef F<Y extends core::num = core::num> = () → Y;
-typedef F2<Y extends core::num = core::num> = () → Y;
+typedef F<Y extends core::num> = () → Y;
+typedef F2<Y extends core::num> = () → Y;
 class A<X extends () → self::A::X = () → dynamic> extends core::Object {
   synthetic constructor •() → self::A<self::A::X>
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/nnbd/issue44455.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/issue44455.dart.weak.outline.expect
index 6628b32..5fc32cd 100644
--- a/pkg/front_end/testcases/nnbd/issue44455.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/issue44455.dart.weak.outline.expect
@@ -21,8 +21,8 @@
 import self as self;
 import "dart:core" as core;
 
-typedef F<Y extends core::num = core::num> = () → Y;
-typedef F2<Y extends core::num = core::num> = () → Y;
+typedef F<Y extends core::num> = () → Y;
+typedef F2<Y extends core::num> = () → Y;
 class A<X extends () → self::A::X = () → dynamic> extends core::Object {
   synthetic constructor •() → self::A<self::A::X>
     ;
diff --git a/pkg/front_end/testcases/nnbd/issue44455.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/issue44455.dart.weak.transformed.expect
index 2d1e9e6..d0065b3 100644
--- a/pkg/front_end/testcases/nnbd/issue44455.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue44455.dart.weak.transformed.expect
@@ -21,8 +21,8 @@
 import self as self;
 import "dart:core" as core;
 
-typedef F<Y extends core::num = core::num> = () → Y;
-typedef F2<Y extends core::num = core::num> = () → Y;
+typedef F<Y extends core::num> = () → Y;
+typedef F2<Y extends core::num> = () → Y;
 class A<X extends () → self::A::X = () → dynamic> extends core::Object {
   synthetic constructor •() → self::A<self::A::X>
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/nnbd/issue44857.dart.weak.expect b/pkg/front_end/testcases/nnbd/issue44857.dart.weak.expect
index ad063b4..bfb240b 100644
--- a/pkg/front_end/testcases/nnbd/issue44857.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/issue44857.dart.weak.expect
@@ -9,5 +9,5 @@
 }
 
 constants  {
-  #C1 = TypeLiteralConstant((<T extends Never* = Never*>(Never*) →* void) →* Never*)
+  #C1 = TypeLiteralConstant((<T extends Never*>(Never*) →* void) →* Never*)
 }
diff --git a/pkg/front_end/testcases/nnbd/issue44857.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/issue44857.dart.weak.transformed.expect
index dd62920..e19c801 100644
--- a/pkg/front_end/testcases/nnbd/issue44857.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue44857.dart.weak.transformed.expect
@@ -9,7 +9,7 @@
 }
 
 constants  {
-  #C1 = TypeLiteralConstant((<T extends Never* = Never*>(Never*) →* void) →* Never*)
+  #C1 = TypeLiteralConstant((<T extends Never*>(Never*) →* void) →* Never*)
 }
 
 Extra constant evaluation status:
diff --git a/pkg/front_end/testcases/nnbd/language_issue1182.dart.strong.expect b/pkg/front_end/testcases/nnbd/language_issue1182.dart.strong.expect
index 2057990..9ffcc4a 100644
--- a/pkg/front_end/testcases/nnbd/language_issue1182.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/language_issue1182.dart.strong.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class Foo<S extends core::num = core::num> extends core::Object {
+class Foo<S extends core::num> extends core::Object {
   synthetic constructor •() → self::Foo<self::Foo::S>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nnbd/language_issue1182.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/language_issue1182.dart.strong.transformed.expect
index 2057990..9ffcc4a 100644
--- a/pkg/front_end/testcases/nnbd/language_issue1182.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/language_issue1182.dart.strong.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class Foo<S extends core::num = core::num> extends core::Object {
+class Foo<S extends core::num> extends core::Object {
   synthetic constructor •() → self::Foo<self::Foo::S>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nnbd/language_issue1182.dart.weak.expect b/pkg/front_end/testcases/nnbd/language_issue1182.dart.weak.expect
index 2057990..9ffcc4a 100644
--- a/pkg/front_end/testcases/nnbd/language_issue1182.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/language_issue1182.dart.weak.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class Foo<S extends core::num = core::num> extends core::Object {
+class Foo<S extends core::num> extends core::Object {
   synthetic constructor •() → self::Foo<self::Foo::S>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nnbd/language_issue1182.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/language_issue1182.dart.weak.outline.expect
index 3cfc9db..1df50f2 100644
--- a/pkg/front_end/testcases/nnbd/language_issue1182.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/language_issue1182.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class Foo<S extends core::num = core::num> extends core::Object {
+class Foo<S extends core::num> extends core::Object {
   synthetic constructor •() → self::Foo<self::Foo::S>
     ;
   method test1(generic-covariant-impl self::Foo::S x) → void
diff --git a/pkg/front_end/testcases/nnbd/language_issue1182.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/language_issue1182.dart.weak.transformed.expect
index 2057990..9ffcc4a 100644
--- a/pkg/front_end/testcases/nnbd/language_issue1182.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/language_issue1182.dart.weak.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class Foo<S extends core::num = core::num> extends core::Object {
+class Foo<S extends core::num> extends core::Object {
   synthetic constructor •() → self::Foo<self::Foo::S>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nnbd/list_constructor.dart.strong.expect b/pkg/front_end/testcases/nnbd/list_constructor.dart.strong.expect
index 43662a2..0a42d2b 100644
--- a/pkg/front_end/testcases/nnbd/list_constructor.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/list_constructor.dart.strong.expect
@@ -20,7 +20,7 @@
 import self as self;
 import "dart:core" as core;
 
-static method foo<T extends core::Object? = core::Object?>() → dynamic {
+static method foo<T extends core::Object?>() → dynamic {
   let final Never #t1 = invalid-expression "pkg/front_end/testcases/nnbd/list_constructor.dart:9:7: Error: Can't use the default List constructor.
 Try using List.filled instead.
   new List<T>(42);
diff --git a/pkg/front_end/testcases/nnbd/list_constructor.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/list_constructor.dart.strong.transformed.expect
index a585522..540795f 100644
--- a/pkg/front_end/testcases/nnbd/list_constructor.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/list_constructor.dart.strong.transformed.expect
@@ -20,7 +20,7 @@
 import self as self;
 import "dart:core" as core;
 
-static method foo<T extends core::Object? = core::Object?>() → dynamic {
+static method foo<T extends core::Object?>() → dynamic {
   let final Never #t1 = invalid-expression "pkg/front_end/testcases/nnbd/list_constructor.dart:9:7: Error: Can't use the default List constructor.
 Try using List.filled instead.
   new List<T>(42);
diff --git a/pkg/front_end/testcases/nnbd/list_constructor.dart.weak.expect b/pkg/front_end/testcases/nnbd/list_constructor.dart.weak.expect
index 43662a2..0a42d2b 100644
--- a/pkg/front_end/testcases/nnbd/list_constructor.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/list_constructor.dart.weak.expect
@@ -20,7 +20,7 @@
 import self as self;
 import "dart:core" as core;
 
-static method foo<T extends core::Object? = core::Object?>() → dynamic {
+static method foo<T extends core::Object?>() → dynamic {
   let final Never #t1 = invalid-expression "pkg/front_end/testcases/nnbd/list_constructor.dart:9:7: Error: Can't use the default List constructor.
 Try using List.filled instead.
   new List<T>(42);
diff --git a/pkg/front_end/testcases/nnbd/list_constructor.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/list_constructor.dart.weak.outline.expect
index b622770..174d1e3 100644
--- a/pkg/front_end/testcases/nnbd/list_constructor.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/list_constructor.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-static method foo<T extends core::Object? = core::Object?>() → dynamic
+static method foo<T extends core::Object?>() → dynamic
   ;
 static method main() → dynamic
   ;
diff --git a/pkg/front_end/testcases/nnbd/list_constructor.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/list_constructor.dart.weak.transformed.expect
index a585522..540795f 100644
--- a/pkg/front_end/testcases/nnbd/list_constructor.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/list_constructor.dart.weak.transformed.expect
@@ -20,7 +20,7 @@
 import self as self;
 import "dart:core" as core;
 
-static method foo<T extends core::Object? = core::Object?>() → dynamic {
+static method foo<T extends core::Object?>() → dynamic {
   let final Never #t1 = invalid-expression "pkg/front_end/testcases/nnbd/list_constructor.dart:9:7: Error: Can't use the default List constructor.
 Try using List.filled instead.
   new List<T>(42);
diff --git a/pkg/front_end/testcases/nnbd/never_bound.dart.strong.expect b/pkg/front_end/testcases/nnbd/never_bound.dart.strong.expect
index ab8cca2..08602d8 100644
--- a/pkg/front_end/testcases/nnbd/never_bound.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/never_bound.dart.strong.expect
@@ -29,7 +29,7 @@
 import self as self;
 import "dart:core" as core;
 
-class GenericNever<T extends Never = Never> extends core::Object {
+class GenericNever<T extends Never> extends core::Object {
   synthetic constructor •() → self::GenericNever<self::GenericNever::T>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nnbd/never_bound.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/never_bound.dart.strong.transformed.expect
index ab8cca2..08602d8 100644
--- a/pkg/front_end/testcases/nnbd/never_bound.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/never_bound.dart.strong.transformed.expect
@@ -29,7 +29,7 @@
 import self as self;
 import "dart:core" as core;
 
-class GenericNever<T extends Never = Never> extends core::Object {
+class GenericNever<T extends Never> extends core::Object {
   synthetic constructor •() → self::GenericNever<self::GenericNever::T>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nnbd/never_bound.dart.weak.expect b/pkg/front_end/testcases/nnbd/never_bound.dart.weak.expect
index ab8cca2..08602d8 100644
--- a/pkg/front_end/testcases/nnbd/never_bound.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/never_bound.dart.weak.expect
@@ -29,7 +29,7 @@
 import self as self;
 import "dart:core" as core;
 
-class GenericNever<T extends Never = Never> extends core::Object {
+class GenericNever<T extends Never> extends core::Object {
   synthetic constructor •() → self::GenericNever<self::GenericNever::T>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nnbd/never_bound.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/never_bound.dart.weak.outline.expect
index 488d8a3..fce0dc8 100644
--- a/pkg/front_end/testcases/nnbd/never_bound.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/never_bound.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class GenericNever<T extends Never = Never> extends core::Object {
+class GenericNever<T extends Never> extends core::Object {
   synthetic constructor •() → self::GenericNever<self::GenericNever::T>
     ;
   method getParamType() → dynamic
diff --git a/pkg/front_end/testcases/nnbd/never_bound.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/never_bound.dart.weak.transformed.expect
index ab8cca2..08602d8 100644
--- a/pkg/front_end/testcases/nnbd/never_bound.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/never_bound.dart.weak.transformed.expect
@@ -29,7 +29,7 @@
 import self as self;
 import "dart:core" as core;
 
-class GenericNever<T extends Never = Never> extends core::Object {
+class GenericNever<T extends Never> extends core::Object {
   synthetic constructor •() → self::GenericNever<self::GenericNever::T>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nnbd/non_nullable_field_initialization.dart.strong.expect b/pkg/front_end/testcases/nnbd/non_nullable_field_initialization.dart.strong.expect
index e9ee16a..19a1ec4 100644
--- a/pkg/front_end/testcases/nnbd/non_nullable_field_initialization.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/non_nullable_field_initialization.dart.strong.expect
@@ -69,7 +69,7 @@
     : self::A::fieldOfA = fieldOfA, super core::Object::•()
     ;
 }
-class B<X extends core::Object? = core::Object?, Y extends core::Object = core::Object> extends core::Object {
+class B<X extends core::Object?, Y extends core::Object> extends core::Object {
   generic-covariant-impl field self::B::X% fieldOfB;
   generic-covariant-impl field self::B::Y fieldOfB2;
   constructor foo() → self::B<self::B::X%, self::B::Y>
@@ -83,11 +83,11 @@
   static field core::int staticFieldOfM = null;
   field core::int fieldOfM = null;
 }
-abstract class N<X extends core::Object? = core::Object?, Y extends core::Object = core::Object> extends core::Object /*isMixinDeclaration*/  {
+abstract class N<X extends core::Object?, Y extends core::Object> extends core::Object /*isMixinDeclaration*/  {
   generic-covariant-impl field self::N::X% fieldOfN = null;
   generic-covariant-impl field self::N::Y fieldOfN2 = null;
 }
-class C<X extends core::Object? = core::Object?, Y extends core::Object = core::Object> extends core::Object {
+class C<X extends core::Object?, Y extends core::Object> extends core::Object {
   static field core::int? staticFieldOfX = null;
   static field core::int staticFieldOfXInitialized = 42;
   generic-covariant-impl field self::C::X? fieldOfX = null;
@@ -108,7 +108,7 @@
     : self::C::fieldOfC10 = fieldOfC10, super core::Object::•()
     ;
 }
-abstract class L<X extends core::Object? = core::Object?, Y extends core::Object = core::Object> extends core::Object /*isMixinDeclaration*/  {
+abstract class L<X extends core::Object?, Y extends core::Object> extends core::Object /*isMixinDeclaration*/  {
   static field core::int? staticFieldOfL = null;
   static field core::int staticFieldOfLInitialized = 42;
   generic-covariant-impl field self::L::X? fieldOfL = null;
diff --git a/pkg/front_end/testcases/nnbd/non_nullable_field_initialization.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/non_nullable_field_initialization.dart.strong.transformed.expect
index e9ee16a..19a1ec4 100644
--- a/pkg/front_end/testcases/nnbd/non_nullable_field_initialization.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/non_nullable_field_initialization.dart.strong.transformed.expect
@@ -69,7 +69,7 @@
     : self::A::fieldOfA = fieldOfA, super core::Object::•()
     ;
 }
-class B<X extends core::Object? = core::Object?, Y extends core::Object = core::Object> extends core::Object {
+class B<X extends core::Object?, Y extends core::Object> extends core::Object {
   generic-covariant-impl field self::B::X% fieldOfB;
   generic-covariant-impl field self::B::Y fieldOfB2;
   constructor foo() → self::B<self::B::X%, self::B::Y>
@@ -83,11 +83,11 @@
   static field core::int staticFieldOfM = null;
   field core::int fieldOfM = null;
 }
-abstract class N<X extends core::Object? = core::Object?, Y extends core::Object = core::Object> extends core::Object /*isMixinDeclaration*/  {
+abstract class N<X extends core::Object?, Y extends core::Object> extends core::Object /*isMixinDeclaration*/  {
   generic-covariant-impl field self::N::X% fieldOfN = null;
   generic-covariant-impl field self::N::Y fieldOfN2 = null;
 }
-class C<X extends core::Object? = core::Object?, Y extends core::Object = core::Object> extends core::Object {
+class C<X extends core::Object?, Y extends core::Object> extends core::Object {
   static field core::int? staticFieldOfX = null;
   static field core::int staticFieldOfXInitialized = 42;
   generic-covariant-impl field self::C::X? fieldOfX = null;
@@ -108,7 +108,7 @@
     : self::C::fieldOfC10 = fieldOfC10, super core::Object::•()
     ;
 }
-abstract class L<X extends core::Object? = core::Object?, Y extends core::Object = core::Object> extends core::Object /*isMixinDeclaration*/  {
+abstract class L<X extends core::Object?, Y extends core::Object> extends core::Object /*isMixinDeclaration*/  {
   static field core::int? staticFieldOfL = null;
   static field core::int staticFieldOfLInitialized = 42;
   generic-covariant-impl field self::L::X? fieldOfL = null;
diff --git a/pkg/front_end/testcases/nnbd/non_nullable_field_initialization.dart.weak.expect b/pkg/front_end/testcases/nnbd/non_nullable_field_initialization.dart.weak.expect
index e9ee16a..19a1ec4 100644
--- a/pkg/front_end/testcases/nnbd/non_nullable_field_initialization.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/non_nullable_field_initialization.dart.weak.expect
@@ -69,7 +69,7 @@
     : self::A::fieldOfA = fieldOfA, super core::Object::•()
     ;
 }
-class B<X extends core::Object? = core::Object?, Y extends core::Object = core::Object> extends core::Object {
+class B<X extends core::Object?, Y extends core::Object> extends core::Object {
   generic-covariant-impl field self::B::X% fieldOfB;
   generic-covariant-impl field self::B::Y fieldOfB2;
   constructor foo() → self::B<self::B::X%, self::B::Y>
@@ -83,11 +83,11 @@
   static field core::int staticFieldOfM = null;
   field core::int fieldOfM = null;
 }
-abstract class N<X extends core::Object? = core::Object?, Y extends core::Object = core::Object> extends core::Object /*isMixinDeclaration*/  {
+abstract class N<X extends core::Object?, Y extends core::Object> extends core::Object /*isMixinDeclaration*/  {
   generic-covariant-impl field self::N::X% fieldOfN = null;
   generic-covariant-impl field self::N::Y fieldOfN2 = null;
 }
-class C<X extends core::Object? = core::Object?, Y extends core::Object = core::Object> extends core::Object {
+class C<X extends core::Object?, Y extends core::Object> extends core::Object {
   static field core::int? staticFieldOfX = null;
   static field core::int staticFieldOfXInitialized = 42;
   generic-covariant-impl field self::C::X? fieldOfX = null;
@@ -108,7 +108,7 @@
     : self::C::fieldOfC10 = fieldOfC10, super core::Object::•()
     ;
 }
-abstract class L<X extends core::Object? = core::Object?, Y extends core::Object = core::Object> extends core::Object /*isMixinDeclaration*/  {
+abstract class L<X extends core::Object?, Y extends core::Object> extends core::Object /*isMixinDeclaration*/  {
   static field core::int? staticFieldOfL = null;
   static field core::int staticFieldOfLInitialized = 42;
   generic-covariant-impl field self::L::X? fieldOfL = null;
diff --git a/pkg/front_end/testcases/nnbd/non_nullable_field_initialization.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/non_nullable_field_initialization.dart.weak.outline.expect
index 03d3614..750e00652 100644
--- a/pkg/front_end/testcases/nnbd/non_nullable_field_initialization.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/non_nullable_field_initialization.dart.weak.outline.expect
@@ -33,7 +33,7 @@
   constructor bar(core::int fieldOfA) → self::A
     ;
 }
-class B<X extends core::Object? = core::Object?, Y extends core::Object = core::Object> extends core::Object {
+class B<X extends core::Object?, Y extends core::Object> extends core::Object {
   generic-covariant-impl field self::B::X% fieldOfB;
   generic-covariant-impl field self::B::Y fieldOfB2;
   constructor foo() → self::B<self::B::X%, self::B::Y>
@@ -45,11 +45,11 @@
   static field core::int staticFieldOfM;
   field core::int fieldOfM;
 }
-abstract class N<X extends core::Object? = core::Object?, Y extends core::Object = core::Object> extends core::Object /*isMixinDeclaration*/  {
+abstract class N<X extends core::Object?, Y extends core::Object> extends core::Object /*isMixinDeclaration*/  {
   generic-covariant-impl field self::N::X% fieldOfN;
   generic-covariant-impl field self::N::Y fieldOfN2;
 }
-class C<X extends core::Object? = core::Object?, Y extends core::Object = core::Object> extends core::Object {
+class C<X extends core::Object?, Y extends core::Object> extends core::Object {
   static field core::int? staticFieldOfX;
   static field core::int staticFieldOfXInitialized;
   generic-covariant-impl field self::C::X? fieldOfX;
@@ -68,7 +68,7 @@
   constructor bar(core::int fieldOfC10) → self::C<self::C::X%, self::C::Y>
     ;
 }
-abstract class L<X extends core::Object? = core::Object?, Y extends core::Object = core::Object> extends core::Object /*isMixinDeclaration*/  {
+abstract class L<X extends core::Object?, Y extends core::Object> extends core::Object /*isMixinDeclaration*/  {
   static field core::int? staticFieldOfL;
   static field core::int staticFieldOfLInitialized;
   generic-covariant-impl field self::L::X? fieldOfL;
diff --git a/pkg/front_end/testcases/nnbd/non_nullable_field_initialization.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/non_nullable_field_initialization.dart.weak.transformed.expect
index e9ee16a..19a1ec4 100644
--- a/pkg/front_end/testcases/nnbd/non_nullable_field_initialization.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/non_nullable_field_initialization.dart.weak.transformed.expect
@@ -69,7 +69,7 @@
     : self::A::fieldOfA = fieldOfA, super core::Object::•()
     ;
 }
-class B<X extends core::Object? = core::Object?, Y extends core::Object = core::Object> extends core::Object {
+class B<X extends core::Object?, Y extends core::Object> extends core::Object {
   generic-covariant-impl field self::B::X% fieldOfB;
   generic-covariant-impl field self::B::Y fieldOfB2;
   constructor foo() → self::B<self::B::X%, self::B::Y>
@@ -83,11 +83,11 @@
   static field core::int staticFieldOfM = null;
   field core::int fieldOfM = null;
 }
-abstract class N<X extends core::Object? = core::Object?, Y extends core::Object = core::Object> extends core::Object /*isMixinDeclaration*/  {
+abstract class N<X extends core::Object?, Y extends core::Object> extends core::Object /*isMixinDeclaration*/  {
   generic-covariant-impl field self::N::X% fieldOfN = null;
   generic-covariant-impl field self::N::Y fieldOfN2 = null;
 }
-class C<X extends core::Object? = core::Object?, Y extends core::Object = core::Object> extends core::Object {
+class C<X extends core::Object?, Y extends core::Object> extends core::Object {
   static field core::int? staticFieldOfX = null;
   static field core::int staticFieldOfXInitialized = 42;
   generic-covariant-impl field self::C::X? fieldOfX = null;
@@ -108,7 +108,7 @@
     : self::C::fieldOfC10 = fieldOfC10, super core::Object::•()
     ;
 }
-abstract class L<X extends core::Object? = core::Object?, Y extends core::Object = core::Object> extends core::Object /*isMixinDeclaration*/  {
+abstract class L<X extends core::Object?, Y extends core::Object> extends core::Object /*isMixinDeclaration*/  {
   static field core::int? staticFieldOfL = null;
   static field core::int staticFieldOfLInitialized = 42;
   generic-covariant-impl field self::L::X? fieldOfL = null;
diff --git a/pkg/front_end/testcases/nnbd/nullable_receiver.dart.strong.expect b/pkg/front_end/testcases/nnbd/nullable_receiver.dart.strong.expect
index 0b89c6b..2c6ff57 100644
--- a/pkg/front_end/testcases/nnbd/nullable_receiver.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/nullable_receiver.dart.strong.expect
@@ -116,7 +116,7 @@
   void Function()? f3 = a;
                         ^" in a as{TypeError} () →? void;
 }
-static method ok<T extends core::Object? = core::Object?>(core::String? s, self::A? a, self::ok::T% t, self::B? b, core::Invocation i) → dynamic {
+static method ok<T extends core::Object?>(core::String? s, self::A? a, self::ok::T% t, self::B? b, core::Invocation i) → dynamic {
   s.{core::String::==}(s);
   a.{core::Object::==}(a);
   t.{core::Object::==}(t);
diff --git a/pkg/front_end/testcases/nnbd/nullable_receiver.dart.weak.expect b/pkg/front_end/testcases/nnbd/nullable_receiver.dart.weak.expect
index 0b89c6b..2c6ff57 100644
--- a/pkg/front_end/testcases/nnbd/nullable_receiver.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/nullable_receiver.dart.weak.expect
@@ -116,7 +116,7 @@
   void Function()? f3 = a;
                         ^" in a as{TypeError} () →? void;
 }
-static method ok<T extends core::Object? = core::Object?>(core::String? s, self::A? a, self::ok::T% t, self::B? b, core::Invocation i) → dynamic {
+static method ok<T extends core::Object?>(core::String? s, self::A? a, self::ok::T% t, self::B? b, core::Invocation i) → dynamic {
   s.{core::String::==}(s);
   a.{core::Object::==}(a);
   t.{core::Object::==}(t);
diff --git a/pkg/front_end/testcases/nnbd/nullable_receiver.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/nullable_receiver.dart.weak.outline.expect
index d88e541e..10a2960 100644
--- a/pkg/front_end/testcases/nnbd/nullable_receiver.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/nullable_receiver.dart.weak.outline.expect
@@ -22,7 +22,7 @@
 }
 static method error(core::String? s, self::A? a, self::B? b) → dynamic
   ;
-static method ok<T extends core::Object? = core::Object?>(core::String? s, self::A? a, self::ok::T% t, self::B? b, core::Invocation i) → dynamic
+static method ok<T extends core::Object?>(core::String? s, self::A? a, self::ok::T% t, self::B? b, core::Invocation i) → dynamic
   ;
 static method main() → dynamic
   ;
diff --git a/pkg/front_end/testcases/nnbd/numbers.dart.strong.expect b/pkg/front_end/testcases/nnbd/numbers.dart.strong.expect
index c539802..d52aac2 100644
--- a/pkg/front_end/testcases/nnbd/numbers.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/numbers.dart.strong.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-static method add<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::add::X x, self::add::Y y, self::add::Z z) → dynamic {
+static method add<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::add::X x, self::add::Y y, self::add::Z z) → dynamic {
   core::num n_n = n.{core::num::+}(n);
   core::num n_i = n.{core::num::+}(i);
   core::double n_d = n.{core::num::+}(d);
@@ -40,7 +40,7 @@
   core::double z_y = z.{core::double::+}(y);
   core::double z_z = z.{core::double::+}(z);
 }
-static method sub<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::sub::X x, self::sub::Y y, self::sub::Z z) → dynamic {
+static method sub<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::sub::X x, self::sub::Y y, self::sub::Z z) → dynamic {
   core::num n_n = n.{core::num::-}(n);
   core::num n_i = n.{core::num::-}(i);
   core::double n_d = n.{core::num::-}(d);
@@ -78,7 +78,7 @@
   core::double z_y = z.{core::double::-}(y);
   core::double z_z = z.{core::double::-}(z);
 }
-static method mul<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::mul::X x, self::mul::Y y, self::mul::Z z) → dynamic {
+static method mul<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::mul::X x, self::mul::Y y, self::mul::Z z) → dynamic {
   core::num n_n = n.{core::num::*}(n);
   core::num n_i = n.{core::num::*}(i);
   core::double n_d = n.{core::num::*}(d);
@@ -116,7 +116,7 @@
   core::double z_y = z.{core::double::*}(y);
   core::double z_z = z.{core::double::*}(z);
 }
-static method mod<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::mod::X x, self::mod::Y y, self::mod::Z z) → dynamic {
+static method mod<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::mod::X x, self::mod::Y y, self::mod::Z z) → dynamic {
   core::num n_n = n.{core::num::%}(n);
   core::num n_i = n.{core::num::%}(i);
   core::double n_d = n.{core::num::%}(d);
@@ -154,7 +154,7 @@
   core::double z_y = z.{core::double::%}(y);
   core::double z_z = z.{core::double::%}(z);
 }
-static method remainder<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::remainder::X x, self::remainder::Y y, self::remainder::Z z) → dynamic {
+static method remainder<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::remainder::X x, self::remainder::Y y, self::remainder::Z z) → dynamic {
   core::num n_n = n.{core::num::remainder}(n);
   core::num n_i = n.{core::num::remainder}(i);
   core::double n_d = n.{core::num::remainder}(d);
@@ -192,7 +192,7 @@
   core::double z_y = z.{core::double::remainder}(y);
   core::double z_z = z.{core::double::remainder}(z);
 }
-static method clamp<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::clamp::X x, self::clamp::Y y, self::clamp::Z z) → dynamic {
+static method clamp<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::clamp::X x, self::clamp::Y y, self::clamp::Z z) → dynamic {
   core::num n_n_n = n.{core::num::clamp}(n, n);
   core::num n_i_n = n.{core::num::clamp}(i, n);
   core::num n_d_n = n.{core::num::clamp}(d, n);
diff --git a/pkg/front_end/testcases/nnbd/numbers.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/numbers.dart.strong.transformed.expect
index c539802..d52aac2 100644
--- a/pkg/front_end/testcases/nnbd/numbers.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/numbers.dart.strong.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-static method add<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::add::X x, self::add::Y y, self::add::Z z) → dynamic {
+static method add<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::add::X x, self::add::Y y, self::add::Z z) → dynamic {
   core::num n_n = n.{core::num::+}(n);
   core::num n_i = n.{core::num::+}(i);
   core::double n_d = n.{core::num::+}(d);
@@ -40,7 +40,7 @@
   core::double z_y = z.{core::double::+}(y);
   core::double z_z = z.{core::double::+}(z);
 }
-static method sub<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::sub::X x, self::sub::Y y, self::sub::Z z) → dynamic {
+static method sub<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::sub::X x, self::sub::Y y, self::sub::Z z) → dynamic {
   core::num n_n = n.{core::num::-}(n);
   core::num n_i = n.{core::num::-}(i);
   core::double n_d = n.{core::num::-}(d);
@@ -78,7 +78,7 @@
   core::double z_y = z.{core::double::-}(y);
   core::double z_z = z.{core::double::-}(z);
 }
-static method mul<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::mul::X x, self::mul::Y y, self::mul::Z z) → dynamic {
+static method mul<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::mul::X x, self::mul::Y y, self::mul::Z z) → dynamic {
   core::num n_n = n.{core::num::*}(n);
   core::num n_i = n.{core::num::*}(i);
   core::double n_d = n.{core::num::*}(d);
@@ -116,7 +116,7 @@
   core::double z_y = z.{core::double::*}(y);
   core::double z_z = z.{core::double::*}(z);
 }
-static method mod<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::mod::X x, self::mod::Y y, self::mod::Z z) → dynamic {
+static method mod<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::mod::X x, self::mod::Y y, self::mod::Z z) → dynamic {
   core::num n_n = n.{core::num::%}(n);
   core::num n_i = n.{core::num::%}(i);
   core::double n_d = n.{core::num::%}(d);
@@ -154,7 +154,7 @@
   core::double z_y = z.{core::double::%}(y);
   core::double z_z = z.{core::double::%}(z);
 }
-static method remainder<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::remainder::X x, self::remainder::Y y, self::remainder::Z z) → dynamic {
+static method remainder<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::remainder::X x, self::remainder::Y y, self::remainder::Z z) → dynamic {
   core::num n_n = n.{core::num::remainder}(n);
   core::num n_i = n.{core::num::remainder}(i);
   core::double n_d = n.{core::num::remainder}(d);
@@ -192,7 +192,7 @@
   core::double z_y = z.{core::double::remainder}(y);
   core::double z_z = z.{core::double::remainder}(z);
 }
-static method clamp<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::clamp::X x, self::clamp::Y y, self::clamp::Z z) → dynamic {
+static method clamp<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::clamp::X x, self::clamp::Y y, self::clamp::Z z) → dynamic {
   core::num n_n_n = n.{core::num::clamp}(n, n);
   core::num n_i_n = n.{core::num::clamp}(i, n);
   core::num n_d_n = n.{core::num::clamp}(d, n);
diff --git a/pkg/front_end/testcases/nnbd/numbers.dart.weak.expect b/pkg/front_end/testcases/nnbd/numbers.dart.weak.expect
index c539802..d52aac2 100644
--- a/pkg/front_end/testcases/nnbd/numbers.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/numbers.dart.weak.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-static method add<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::add::X x, self::add::Y y, self::add::Z z) → dynamic {
+static method add<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::add::X x, self::add::Y y, self::add::Z z) → dynamic {
   core::num n_n = n.{core::num::+}(n);
   core::num n_i = n.{core::num::+}(i);
   core::double n_d = n.{core::num::+}(d);
@@ -40,7 +40,7 @@
   core::double z_y = z.{core::double::+}(y);
   core::double z_z = z.{core::double::+}(z);
 }
-static method sub<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::sub::X x, self::sub::Y y, self::sub::Z z) → dynamic {
+static method sub<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::sub::X x, self::sub::Y y, self::sub::Z z) → dynamic {
   core::num n_n = n.{core::num::-}(n);
   core::num n_i = n.{core::num::-}(i);
   core::double n_d = n.{core::num::-}(d);
@@ -78,7 +78,7 @@
   core::double z_y = z.{core::double::-}(y);
   core::double z_z = z.{core::double::-}(z);
 }
-static method mul<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::mul::X x, self::mul::Y y, self::mul::Z z) → dynamic {
+static method mul<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::mul::X x, self::mul::Y y, self::mul::Z z) → dynamic {
   core::num n_n = n.{core::num::*}(n);
   core::num n_i = n.{core::num::*}(i);
   core::double n_d = n.{core::num::*}(d);
@@ -116,7 +116,7 @@
   core::double z_y = z.{core::double::*}(y);
   core::double z_z = z.{core::double::*}(z);
 }
-static method mod<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::mod::X x, self::mod::Y y, self::mod::Z z) → dynamic {
+static method mod<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::mod::X x, self::mod::Y y, self::mod::Z z) → dynamic {
   core::num n_n = n.{core::num::%}(n);
   core::num n_i = n.{core::num::%}(i);
   core::double n_d = n.{core::num::%}(d);
@@ -154,7 +154,7 @@
   core::double z_y = z.{core::double::%}(y);
   core::double z_z = z.{core::double::%}(z);
 }
-static method remainder<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::remainder::X x, self::remainder::Y y, self::remainder::Z z) → dynamic {
+static method remainder<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::remainder::X x, self::remainder::Y y, self::remainder::Z z) → dynamic {
   core::num n_n = n.{core::num::remainder}(n);
   core::num n_i = n.{core::num::remainder}(i);
   core::double n_d = n.{core::num::remainder}(d);
@@ -192,7 +192,7 @@
   core::double z_y = z.{core::double::remainder}(y);
   core::double z_z = z.{core::double::remainder}(z);
 }
-static method clamp<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::clamp::X x, self::clamp::Y y, self::clamp::Z z) → dynamic {
+static method clamp<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::clamp::X x, self::clamp::Y y, self::clamp::Z z) → dynamic {
   core::num n_n_n = n.{core::num::clamp}(n, n);
   core::num n_i_n = n.{core::num::clamp}(i, n);
   core::num n_d_n = n.{core::num::clamp}(d, n);
diff --git a/pkg/front_end/testcases/nnbd/numbers.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/numbers.dart.weak.outline.expect
index e9834e0..bfe6473 100644
--- a/pkg/front_end/testcases/nnbd/numbers.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/numbers.dart.weak.outline.expect
@@ -2,17 +2,17 @@
 import self as self;
 import "dart:core" as core;
 
-static method add<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::add::X x, self::add::Y y, self::add::Z z) → dynamic
+static method add<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::add::X x, self::add::Y y, self::add::Z z) → dynamic
   ;
-static method sub<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::sub::X x, self::sub::Y y, self::sub::Z z) → dynamic
+static method sub<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::sub::X x, self::sub::Y y, self::sub::Z z) → dynamic
   ;
-static method mul<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::mul::X x, self::mul::Y y, self::mul::Z z) → dynamic
+static method mul<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::mul::X x, self::mul::Y y, self::mul::Z z) → dynamic
   ;
-static method mod<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::mod::X x, self::mod::Y y, self::mod::Z z) → dynamic
+static method mod<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::mod::X x, self::mod::Y y, self::mod::Z z) → dynamic
   ;
-static method remainder<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::remainder::X x, self::remainder::Y y, self::remainder::Z z) → dynamic
+static method remainder<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::remainder::X x, self::remainder::Y y, self::remainder::Z z) → dynamic
   ;
-static method clamp<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::clamp::X x, self::clamp::Y y, self::clamp::Z z) → dynamic
+static method clamp<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::clamp::X x, self::clamp::Y y, self::clamp::Z z) → dynamic
   ;
 static method main() → dynamic
   ;
diff --git a/pkg/front_end/testcases/nnbd/numbers.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/numbers.dart.weak.transformed.expect
index c539802..d52aac2 100644
--- a/pkg/front_end/testcases/nnbd/numbers.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/numbers.dart.weak.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-static method add<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::add::X x, self::add::Y y, self::add::Z z) → dynamic {
+static method add<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::add::X x, self::add::Y y, self::add::Z z) → dynamic {
   core::num n_n = n.{core::num::+}(n);
   core::num n_i = n.{core::num::+}(i);
   core::double n_d = n.{core::num::+}(d);
@@ -40,7 +40,7 @@
   core::double z_y = z.{core::double::+}(y);
   core::double z_z = z.{core::double::+}(z);
 }
-static method sub<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::sub::X x, self::sub::Y y, self::sub::Z z) → dynamic {
+static method sub<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::sub::X x, self::sub::Y y, self::sub::Z z) → dynamic {
   core::num n_n = n.{core::num::-}(n);
   core::num n_i = n.{core::num::-}(i);
   core::double n_d = n.{core::num::-}(d);
@@ -78,7 +78,7 @@
   core::double z_y = z.{core::double::-}(y);
   core::double z_z = z.{core::double::-}(z);
 }
-static method mul<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::mul::X x, self::mul::Y y, self::mul::Z z) → dynamic {
+static method mul<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::mul::X x, self::mul::Y y, self::mul::Z z) → dynamic {
   core::num n_n = n.{core::num::*}(n);
   core::num n_i = n.{core::num::*}(i);
   core::double n_d = n.{core::num::*}(d);
@@ -116,7 +116,7 @@
   core::double z_y = z.{core::double::*}(y);
   core::double z_z = z.{core::double::*}(z);
 }
-static method mod<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::mod::X x, self::mod::Y y, self::mod::Z z) → dynamic {
+static method mod<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::mod::X x, self::mod::Y y, self::mod::Z z) → dynamic {
   core::num n_n = n.{core::num::%}(n);
   core::num n_i = n.{core::num::%}(i);
   core::double n_d = n.{core::num::%}(d);
@@ -154,7 +154,7 @@
   core::double z_y = z.{core::double::%}(y);
   core::double z_z = z.{core::double::%}(z);
 }
-static method remainder<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::remainder::X x, self::remainder::Y y, self::remainder::Z z) → dynamic {
+static method remainder<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::remainder::X x, self::remainder::Y y, self::remainder::Z z) → dynamic {
   core::num n_n = n.{core::num::remainder}(n);
   core::num n_i = n.{core::num::remainder}(i);
   core::double n_d = n.{core::num::remainder}(d);
@@ -192,7 +192,7 @@
   core::double z_y = z.{core::double::remainder}(y);
   core::double z_z = z.{core::double::remainder}(z);
 }
-static method clamp<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::clamp::X x, self::clamp::Y y, self::clamp::Z z) → dynamic {
+static method clamp<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::clamp::X x, self::clamp::Y y, self::clamp::Z z) → dynamic {
   core::num n_n_n = n.{core::num::clamp}(n, n);
   core::num n_i_n = n.{core::num::clamp}(i, n);
   core::num n_d_n = n.{core::num::clamp}(d, n);
diff --git a/pkg/front_end/testcases/nnbd/numbers_inferred.dart.strong.expect b/pkg/front_end/testcases/nnbd/numbers_inferred.dart.strong.expect
index dd84efc..cdda24f 100644
--- a/pkg/front_end/testcases/nnbd/numbers_inferred.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/numbers_inferred.dart.strong.expect
@@ -551,7 +551,7 @@
 
 static method f<T extends core::Object? = dynamic>() → self::f::T%
   return throw "Unsupported";
-static method add<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::add::X x, self::add::Y y, self::add::Z z) → dynamic {
+static method add<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::add::X x, self::add::Y y, self::add::Z z) → dynamic {
   core::num n_n = n.{core::num::+}(self::f<core::num>());
   core::int n_i = let final Never #t1 = invalid-expression "pkg/front_end/testcases/nnbd/numbers_inferred.dart:10:15: Error: A value of type 'num' can't be assigned to a variable of type 'int'.
   int n_i = n + f();
@@ -633,7 +633,7 @@
   Z z_z = z + f();
             ^" in z.{core::double::+}(self::f<core::num>()) as{TypeError,ForNonNullableByDefault} Never;
 }
-static method sub<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::sub::X x, self::sub::Y y, self::sub::Z z) → dynamic {
+static method sub<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::sub::X x, self::sub::Y y, self::sub::Z z) → dynamic {
   core::num n_n = n.{core::num::-}(self::f<core::num>());
   core::int n_i = let final Never #t23 = invalid-expression "pkg/front_end/testcases/nnbd/numbers_inferred.dart:55:15: Error: A value of type 'num' can't be assigned to a variable of type 'int'.
   int n_i = n - f();
@@ -715,7 +715,7 @@
   Z z_z = z - f();
             ^" in z.{core::double::-}(self::f<core::num>()) as{TypeError,ForNonNullableByDefault} Never;
 }
-static method mul<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::mul::X x, self::mul::Y y, self::mul::Z z) → dynamic {
+static method mul<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::mul::X x, self::mul::Y y, self::mul::Z z) → dynamic {
   core::num n_n = n.{core::num::*}(self::f<core::num>());
   core::int n_i = let final Never #t45 = invalid-expression "pkg/front_end/testcases/nnbd/numbers_inferred.dart:100:15: Error: A value of type 'num' can't be assigned to a variable of type 'int'.
   int n_i = n * f();
@@ -797,7 +797,7 @@
   Z z_z = z * f();
             ^" in z.{core::double::*}(self::f<core::num>()) as{TypeError,ForNonNullableByDefault} Never;
 }
-static method mod<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::mod::X x, self::mod::Y y, self::mod::Z z) → dynamic {
+static method mod<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::mod::X x, self::mod::Y y, self::mod::Z z) → dynamic {
   core::num n_n = n.{core::num::%}(self::f<core::num>());
   core::int n_i = let final Never #t67 = invalid-expression "pkg/front_end/testcases/nnbd/numbers_inferred.dart:145:15: Error: A value of type 'num' can't be assigned to a variable of type 'int'.
   int n_i = n % f();
@@ -879,7 +879,7 @@
   Z z_z = z % f();
             ^" in z.{core::double::%}(self::f<core::num>()) as{TypeError,ForNonNullableByDefault} Never;
 }
-static method remainder<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::remainder::X x, self::remainder::Y y, self::remainder::Z z) → dynamic {
+static method remainder<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::remainder::X x, self::remainder::Y y, self::remainder::Z z) → dynamic {
   core::num n_n = n.{core::num::remainder}(self::f<core::num>());
   core::int n_i = let final Never #t89 = invalid-expression "pkg/front_end/testcases/nnbd/numbers_inferred.dart:190:15: Error: A value of type 'num' can't be assigned to a variable of type 'int'.
   int n_i = n.remainder(f());
@@ -961,7 +961,7 @@
   Z z_z = z.remainder(f());
             ^" in z.{core::double::remainder}(self::f<core::num>()) as{TypeError,ForNonNullableByDefault} Never;
 }
-static method clamp<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::clamp::X x, self::clamp::Y y, self::clamp::Z z) → dynamic {
+static method clamp<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::clamp::X x, self::clamp::Y y, self::clamp::Z z) → dynamic {
   core::num n_n = n.{core::num::clamp}(self::f<core::num>(), self::f<core::num>());
   core::int n_i = let final Never #t111 = invalid-expression "pkg/front_end/testcases/nnbd/numbers_inferred.dart:235:15: Error: A value of type 'num' can't be assigned to a variable of type 'int'.
   int n_i = n.clamp(f(), f());
diff --git a/pkg/front_end/testcases/nnbd/numbers_inferred.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/numbers_inferred.dart.strong.transformed.expect
index dd84efc..cdda24f 100644
--- a/pkg/front_end/testcases/nnbd/numbers_inferred.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/numbers_inferred.dart.strong.transformed.expect
@@ -551,7 +551,7 @@
 
 static method f<T extends core::Object? = dynamic>() → self::f::T%
   return throw "Unsupported";
-static method add<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::add::X x, self::add::Y y, self::add::Z z) → dynamic {
+static method add<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::add::X x, self::add::Y y, self::add::Z z) → dynamic {
   core::num n_n = n.{core::num::+}(self::f<core::num>());
   core::int n_i = let final Never #t1 = invalid-expression "pkg/front_end/testcases/nnbd/numbers_inferred.dart:10:15: Error: A value of type 'num' can't be assigned to a variable of type 'int'.
   int n_i = n + f();
@@ -633,7 +633,7 @@
   Z z_z = z + f();
             ^" in z.{core::double::+}(self::f<core::num>()) as{TypeError,ForNonNullableByDefault} Never;
 }
-static method sub<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::sub::X x, self::sub::Y y, self::sub::Z z) → dynamic {
+static method sub<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::sub::X x, self::sub::Y y, self::sub::Z z) → dynamic {
   core::num n_n = n.{core::num::-}(self::f<core::num>());
   core::int n_i = let final Never #t23 = invalid-expression "pkg/front_end/testcases/nnbd/numbers_inferred.dart:55:15: Error: A value of type 'num' can't be assigned to a variable of type 'int'.
   int n_i = n - f();
@@ -715,7 +715,7 @@
   Z z_z = z - f();
             ^" in z.{core::double::-}(self::f<core::num>()) as{TypeError,ForNonNullableByDefault} Never;
 }
-static method mul<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::mul::X x, self::mul::Y y, self::mul::Z z) → dynamic {
+static method mul<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::mul::X x, self::mul::Y y, self::mul::Z z) → dynamic {
   core::num n_n = n.{core::num::*}(self::f<core::num>());
   core::int n_i = let final Never #t45 = invalid-expression "pkg/front_end/testcases/nnbd/numbers_inferred.dart:100:15: Error: A value of type 'num' can't be assigned to a variable of type 'int'.
   int n_i = n * f();
@@ -797,7 +797,7 @@
   Z z_z = z * f();
             ^" in z.{core::double::*}(self::f<core::num>()) as{TypeError,ForNonNullableByDefault} Never;
 }
-static method mod<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::mod::X x, self::mod::Y y, self::mod::Z z) → dynamic {
+static method mod<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::mod::X x, self::mod::Y y, self::mod::Z z) → dynamic {
   core::num n_n = n.{core::num::%}(self::f<core::num>());
   core::int n_i = let final Never #t67 = invalid-expression "pkg/front_end/testcases/nnbd/numbers_inferred.dart:145:15: Error: A value of type 'num' can't be assigned to a variable of type 'int'.
   int n_i = n % f();
@@ -879,7 +879,7 @@
   Z z_z = z % f();
             ^" in z.{core::double::%}(self::f<core::num>()) as{TypeError,ForNonNullableByDefault} Never;
 }
-static method remainder<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::remainder::X x, self::remainder::Y y, self::remainder::Z z) → dynamic {
+static method remainder<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::remainder::X x, self::remainder::Y y, self::remainder::Z z) → dynamic {
   core::num n_n = n.{core::num::remainder}(self::f<core::num>());
   core::int n_i = let final Never #t89 = invalid-expression "pkg/front_end/testcases/nnbd/numbers_inferred.dart:190:15: Error: A value of type 'num' can't be assigned to a variable of type 'int'.
   int n_i = n.remainder(f());
@@ -961,7 +961,7 @@
   Z z_z = z.remainder(f());
             ^" in z.{core::double::remainder}(self::f<core::num>()) as{TypeError,ForNonNullableByDefault} Never;
 }
-static method clamp<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::clamp::X x, self::clamp::Y y, self::clamp::Z z) → dynamic {
+static method clamp<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::clamp::X x, self::clamp::Y y, self::clamp::Z z) → dynamic {
   core::num n_n = n.{core::num::clamp}(self::f<core::num>(), self::f<core::num>());
   core::int n_i = let final Never #t111 = invalid-expression "pkg/front_end/testcases/nnbd/numbers_inferred.dart:235:15: Error: A value of type 'num' can't be assigned to a variable of type 'int'.
   int n_i = n.clamp(f(), f());
diff --git a/pkg/front_end/testcases/nnbd/numbers_inferred.dart.weak.expect b/pkg/front_end/testcases/nnbd/numbers_inferred.dart.weak.expect
index dd84efc..cdda24f 100644
--- a/pkg/front_end/testcases/nnbd/numbers_inferred.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/numbers_inferred.dart.weak.expect
@@ -551,7 +551,7 @@
 
 static method f<T extends core::Object? = dynamic>() → self::f::T%
   return throw "Unsupported";
-static method add<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::add::X x, self::add::Y y, self::add::Z z) → dynamic {
+static method add<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::add::X x, self::add::Y y, self::add::Z z) → dynamic {
   core::num n_n = n.{core::num::+}(self::f<core::num>());
   core::int n_i = let final Never #t1 = invalid-expression "pkg/front_end/testcases/nnbd/numbers_inferred.dart:10:15: Error: A value of type 'num' can't be assigned to a variable of type 'int'.
   int n_i = n + f();
@@ -633,7 +633,7 @@
   Z z_z = z + f();
             ^" in z.{core::double::+}(self::f<core::num>()) as{TypeError,ForNonNullableByDefault} Never;
 }
-static method sub<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::sub::X x, self::sub::Y y, self::sub::Z z) → dynamic {
+static method sub<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::sub::X x, self::sub::Y y, self::sub::Z z) → dynamic {
   core::num n_n = n.{core::num::-}(self::f<core::num>());
   core::int n_i = let final Never #t23 = invalid-expression "pkg/front_end/testcases/nnbd/numbers_inferred.dart:55:15: Error: A value of type 'num' can't be assigned to a variable of type 'int'.
   int n_i = n - f();
@@ -715,7 +715,7 @@
   Z z_z = z - f();
             ^" in z.{core::double::-}(self::f<core::num>()) as{TypeError,ForNonNullableByDefault} Never;
 }
-static method mul<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::mul::X x, self::mul::Y y, self::mul::Z z) → dynamic {
+static method mul<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::mul::X x, self::mul::Y y, self::mul::Z z) → dynamic {
   core::num n_n = n.{core::num::*}(self::f<core::num>());
   core::int n_i = let final Never #t45 = invalid-expression "pkg/front_end/testcases/nnbd/numbers_inferred.dart:100:15: Error: A value of type 'num' can't be assigned to a variable of type 'int'.
   int n_i = n * f();
@@ -797,7 +797,7 @@
   Z z_z = z * f();
             ^" in z.{core::double::*}(self::f<core::num>()) as{TypeError,ForNonNullableByDefault} Never;
 }
-static method mod<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::mod::X x, self::mod::Y y, self::mod::Z z) → dynamic {
+static method mod<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::mod::X x, self::mod::Y y, self::mod::Z z) → dynamic {
   core::num n_n = n.{core::num::%}(self::f<core::num>());
   core::int n_i = let final Never #t67 = invalid-expression "pkg/front_end/testcases/nnbd/numbers_inferred.dart:145:15: Error: A value of type 'num' can't be assigned to a variable of type 'int'.
   int n_i = n % f();
@@ -879,7 +879,7 @@
   Z z_z = z % f();
             ^" in z.{core::double::%}(self::f<core::num>()) as{TypeError,ForNonNullableByDefault} Never;
 }
-static method remainder<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::remainder::X x, self::remainder::Y y, self::remainder::Z z) → dynamic {
+static method remainder<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::remainder::X x, self::remainder::Y y, self::remainder::Z z) → dynamic {
   core::num n_n = n.{core::num::remainder}(self::f<core::num>());
   core::int n_i = let final Never #t89 = invalid-expression "pkg/front_end/testcases/nnbd/numbers_inferred.dart:190:15: Error: A value of type 'num' can't be assigned to a variable of type 'int'.
   int n_i = n.remainder(f());
@@ -961,7 +961,7 @@
   Z z_z = z.remainder(f());
             ^" in z.{core::double::remainder}(self::f<core::num>()) as{TypeError,ForNonNullableByDefault} Never;
 }
-static method clamp<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::clamp::X x, self::clamp::Y y, self::clamp::Z z) → dynamic {
+static method clamp<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::clamp::X x, self::clamp::Y y, self::clamp::Z z) → dynamic {
   core::num n_n = n.{core::num::clamp}(self::f<core::num>(), self::f<core::num>());
   core::int n_i = let final Never #t111 = invalid-expression "pkg/front_end/testcases/nnbd/numbers_inferred.dart:235:15: Error: A value of type 'num' can't be assigned to a variable of type 'int'.
   int n_i = n.clamp(f(), f());
diff --git a/pkg/front_end/testcases/nnbd/numbers_inferred.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/numbers_inferred.dart.weak.outline.expect
index 8160ab1..f479d6e 100644
--- a/pkg/front_end/testcases/nnbd/numbers_inferred.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/numbers_inferred.dart.weak.outline.expect
@@ -4,17 +4,17 @@
 
 static method f<T extends core::Object? = dynamic>() → self::f::T%
   ;
-static method add<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::add::X x, self::add::Y y, self::add::Z z) → dynamic
+static method add<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::add::X x, self::add::Y y, self::add::Z z) → dynamic
   ;
-static method sub<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::sub::X x, self::sub::Y y, self::sub::Z z) → dynamic
+static method sub<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::sub::X x, self::sub::Y y, self::sub::Z z) → dynamic
   ;
-static method mul<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::mul::X x, self::mul::Y y, self::mul::Z z) → dynamic
+static method mul<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::mul::X x, self::mul::Y y, self::mul::Z z) → dynamic
   ;
-static method mod<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::mod::X x, self::mod::Y y, self::mod::Z z) → dynamic
+static method mod<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::mod::X x, self::mod::Y y, self::mod::Z z) → dynamic
   ;
-static method remainder<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::remainder::X x, self::remainder::Y y, self::remainder::Z z) → dynamic
+static method remainder<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::remainder::X x, self::remainder::Y y, self::remainder::Z z) → dynamic
   ;
-static method clamp<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::clamp::X x, self::clamp::Y y, self::clamp::Z z) → dynamic
+static method clamp<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::clamp::X x, self::clamp::Y y, self::clamp::Z z) → dynamic
   ;
 static method main() → dynamic
   ;
diff --git a/pkg/front_end/testcases/nnbd/numbers_inferred.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/numbers_inferred.dart.weak.transformed.expect
index dd84efc..cdda24f 100644
--- a/pkg/front_end/testcases/nnbd/numbers_inferred.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/numbers_inferred.dart.weak.transformed.expect
@@ -551,7 +551,7 @@
 
 static method f<T extends core::Object? = dynamic>() → self::f::T%
   return throw "Unsupported";
-static method add<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::add::X x, self::add::Y y, self::add::Z z) → dynamic {
+static method add<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::add::X x, self::add::Y y, self::add::Z z) → dynamic {
   core::num n_n = n.{core::num::+}(self::f<core::num>());
   core::int n_i = let final Never #t1 = invalid-expression "pkg/front_end/testcases/nnbd/numbers_inferred.dart:10:15: Error: A value of type 'num' can't be assigned to a variable of type 'int'.
   int n_i = n + f();
@@ -633,7 +633,7 @@
   Z z_z = z + f();
             ^" in z.{core::double::+}(self::f<core::num>()) as{TypeError,ForNonNullableByDefault} Never;
 }
-static method sub<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::sub::X x, self::sub::Y y, self::sub::Z z) → dynamic {
+static method sub<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::sub::X x, self::sub::Y y, self::sub::Z z) → dynamic {
   core::num n_n = n.{core::num::-}(self::f<core::num>());
   core::int n_i = let final Never #t23 = invalid-expression "pkg/front_end/testcases/nnbd/numbers_inferred.dart:55:15: Error: A value of type 'num' can't be assigned to a variable of type 'int'.
   int n_i = n - f();
@@ -715,7 +715,7 @@
   Z z_z = z - f();
             ^" in z.{core::double::-}(self::f<core::num>()) as{TypeError,ForNonNullableByDefault} Never;
 }
-static method mul<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::mul::X x, self::mul::Y y, self::mul::Z z) → dynamic {
+static method mul<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::mul::X x, self::mul::Y y, self::mul::Z z) → dynamic {
   core::num n_n = n.{core::num::*}(self::f<core::num>());
   core::int n_i = let final Never #t45 = invalid-expression "pkg/front_end/testcases/nnbd/numbers_inferred.dart:100:15: Error: A value of type 'num' can't be assigned to a variable of type 'int'.
   int n_i = n * f();
@@ -797,7 +797,7 @@
   Z z_z = z * f();
             ^" in z.{core::double::*}(self::f<core::num>()) as{TypeError,ForNonNullableByDefault} Never;
 }
-static method mod<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::mod::X x, self::mod::Y y, self::mod::Z z) → dynamic {
+static method mod<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::mod::X x, self::mod::Y y, self::mod::Z z) → dynamic {
   core::num n_n = n.{core::num::%}(self::f<core::num>());
   core::int n_i = let final Never #t67 = invalid-expression "pkg/front_end/testcases/nnbd/numbers_inferred.dart:145:15: Error: A value of type 'num' can't be assigned to a variable of type 'int'.
   int n_i = n % f();
@@ -879,7 +879,7 @@
   Z z_z = z % f();
             ^" in z.{core::double::%}(self::f<core::num>()) as{TypeError,ForNonNullableByDefault} Never;
 }
-static method remainder<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::remainder::X x, self::remainder::Y y, self::remainder::Z z) → dynamic {
+static method remainder<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::remainder::X x, self::remainder::Y y, self::remainder::Z z) → dynamic {
   core::num n_n = n.{core::num::remainder}(self::f<core::num>());
   core::int n_i = let final Never #t89 = invalid-expression "pkg/front_end/testcases/nnbd/numbers_inferred.dart:190:15: Error: A value of type 'num' can't be assigned to a variable of type 'int'.
   int n_i = n.remainder(f());
@@ -961,7 +961,7 @@
   Z z_z = z.remainder(f());
             ^" in z.{core::double::remainder}(self::f<core::num>()) as{TypeError,ForNonNullableByDefault} Never;
 }
-static method clamp<X extends core::num = core::num, Y extends core::int = core::int, Z extends core::double = core::double>(core::num n, core::int i, core::double d, self::clamp::X x, self::clamp::Y y, self::clamp::Z z) → dynamic {
+static method clamp<X extends core::num, Y extends core::int, Z extends core::double>(core::num n, core::int i, core::double d, self::clamp::X x, self::clamp::Y y, self::clamp::Z z) → dynamic {
   core::num n_n = n.{core::num::clamp}(self::f<core::num>(), self::f<core::num>());
   core::int n_i = let final Never #t111 = invalid-expression "pkg/front_end/testcases/nnbd/numbers_inferred.dart:235:15: Error: A value of type 'num' can't be assigned to a variable of type 'int'.
   int n_i = n.clamp(f(), f());
diff --git a/pkg/front_end/testcases/nnbd/override_checks.dart.strong.expect b/pkg/front_end/testcases/nnbd/override_checks.dart.strong.expect
index 6721314..661f38d 100644
--- a/pkg/front_end/testcases/nnbd/override_checks.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/override_checks.dart.strong.expect
@@ -38,7 +38,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<X extends core::num = core::num> extends core::Object {
+class A<X extends core::num> extends core::Object {
   synthetic constructor •() → self::A<self::A::X>
     : super core::Object::•()
     ;
@@ -66,7 +66,7 @@
   static factory •() → self::C1
     let dynamic #redirecting_factory = self::C2::• in let core::int? #typeArg0 = null in invalid-expression;
 }
-class C2<X extends core::int = core::int> extends core::Object implements self::C1 {
+class C2<X extends core::int> extends core::Object implements self::C1 {
   synthetic constructor •() → self::C2<self::C2::X>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nnbd/override_checks.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/override_checks.dart.strong.transformed.expect
index 8c716e6..1ac0b20 100644
--- a/pkg/front_end/testcases/nnbd/override_checks.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/override_checks.dart.strong.transformed.expect
@@ -38,7 +38,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<X extends core::num = core::num> extends core::Object {
+class A<X extends core::num> extends core::Object {
   synthetic constructor •() → self::A<self::A::X>
     : super core::Object::•()
     ;
@@ -66,7 +66,7 @@
   static factory •() → self::C1
     let Never #redirecting_factory = self::C2::• in let core::int? #typeArg0 = null in invalid-expression;
 }
-class C2<X extends core::int = core::int> extends core::Object implements self::C1 {
+class C2<X extends core::int> extends core::Object implements self::C1 {
   synthetic constructor •() → self::C2<self::C2::X>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nnbd/override_checks.dart.weak.expect b/pkg/front_end/testcases/nnbd/override_checks.dart.weak.expect
index 6721314..661f38d 100644
--- a/pkg/front_end/testcases/nnbd/override_checks.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/override_checks.dart.weak.expect
@@ -38,7 +38,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<X extends core::num = core::num> extends core::Object {
+class A<X extends core::num> extends core::Object {
   synthetic constructor •() → self::A<self::A::X>
     : super core::Object::•()
     ;
@@ -66,7 +66,7 @@
   static factory •() → self::C1
     let dynamic #redirecting_factory = self::C2::• in let core::int? #typeArg0 = null in invalid-expression;
 }
-class C2<X extends core::int = core::int> extends core::Object implements self::C1 {
+class C2<X extends core::int> extends core::Object implements self::C1 {
   synthetic constructor •() → self::C2<self::C2::X>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nnbd/override_checks.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/override_checks.dart.weak.outline.expect
index ece5e4e..c5c7f90 100644
--- a/pkg/front_end/testcases/nnbd/override_checks.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/override_checks.dart.weak.outline.expect
@@ -38,7 +38,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<X extends core::num = core::num> extends core::Object {
+class A<X extends core::num> extends core::Object {
   synthetic constructor •() → self::A<self::A::X>
     ;
 }
@@ -66,7 +66,7 @@
   static factory •() → self::C1
     let dynamic #redirecting_factory = self::C2::• in let core::int? #typeArg0 = null in invalid-expression;
 }
-class C2<X extends core::int = core::int> extends core::Object implements self::C1 {
+class C2<X extends core::int> extends core::Object implements self::C1 {
   synthetic constructor •() → self::C2<self::C2::X>
     ;
 }
diff --git a/pkg/front_end/testcases/nnbd/override_checks.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/override_checks.dart.weak.transformed.expect
index 8c716e6..1ac0b20 100644
--- a/pkg/front_end/testcases/nnbd/override_checks.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/override_checks.dart.weak.transformed.expect
@@ -38,7 +38,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<X extends core::num = core::num> extends core::Object {
+class A<X extends core::num> extends core::Object {
   synthetic constructor •() → self::A<self::A::X>
     : super core::Object::•()
     ;
@@ -66,7 +66,7 @@
   static factory •() → self::C1
     let Never #redirecting_factory = self::C2::• in let core::int? #typeArg0 = null in invalid-expression;
 }
-class C2<X extends core::int = core::int> extends core::Object implements self::C1 {
+class C2<X extends core::int> extends core::Object implements self::C1 {
   synthetic constructor •() → self::C2<self::C2::X>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nnbd/platform_definite_assignment/main.dart.strong.expect b/pkg/front_end/testcases/nnbd/platform_definite_assignment/main.dart.strong.expect
index 32a8f57..631f443 100644
--- a/pkg/front_end/testcases/nnbd/platform_definite_assignment/main.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/platform_definite_assignment/main.dart.strong.expect
@@ -52,7 +52,7 @@
 import "dart:_internal";
 
 @#C1
-class Class<T extends core::num = core::num> extends core::Object /*hasConstConstructor*/  {
+class Class<T extends core::num> extends core::Object /*hasConstConstructor*/  {
   final field core::int a;
   final field test::Class::T b;
   const constructor constConstructor(core::int a, test::Class::T b) → test::Class<test::Class::T>
diff --git a/pkg/front_end/testcases/nnbd/platform_definite_assignment/main.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/platform_definite_assignment/main.dart.strong.transformed.expect
index 32a8f57..631f443 100644
--- a/pkg/front_end/testcases/nnbd/platform_definite_assignment/main.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/platform_definite_assignment/main.dart.strong.transformed.expect
@@ -52,7 +52,7 @@
 import "dart:_internal";
 
 @#C1
-class Class<T extends core::num = core::num> extends core::Object /*hasConstConstructor*/  {
+class Class<T extends core::num> extends core::Object /*hasConstConstructor*/  {
   final field core::int a;
   final field test::Class::T b;
   const constructor constConstructor(core::int a, test::Class::T b) → test::Class<test::Class::T>
diff --git a/pkg/front_end/testcases/nnbd/platform_definite_assignment/main.dart.weak.expect b/pkg/front_end/testcases/nnbd/platform_definite_assignment/main.dart.weak.expect
index 32a8f57..631f443 100644
--- a/pkg/front_end/testcases/nnbd/platform_definite_assignment/main.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/platform_definite_assignment/main.dart.weak.expect
@@ -52,7 +52,7 @@
 import "dart:_internal";
 
 @#C1
-class Class<T extends core::num = core::num> extends core::Object /*hasConstConstructor*/  {
+class Class<T extends core::num> extends core::Object /*hasConstConstructor*/  {
   final field core::int a;
   final field test::Class::T b;
   const constructor constConstructor(core::int a, test::Class::T b) → test::Class<test::Class::T>
diff --git a/pkg/front_end/testcases/nnbd/platform_definite_assignment/main.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/platform_definite_assignment/main.dart.weak.outline.expect
index f5a5f71..079de64 100644
--- a/pkg/front_end/testcases/nnbd/platform_definite_assignment/main.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/platform_definite_assignment/main.dart.weak.outline.expect
@@ -14,7 +14,7 @@
 import "dart:_internal";
 
 @_in::patch
-class Class<T extends core::num = core::num> extends core::Object /*hasConstConstructor*/  {
+class Class<T extends core::num> extends core::Object /*hasConstConstructor*/  {
   final field core::int a;
   final field self2::Class::T b;
   const constructor constConstructor(core::int a, self2::Class::T b) → self2::Class<self2::Class::T>
diff --git a/pkg/front_end/testcases/nnbd/platform_definite_assignment/main.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/platform_definite_assignment/main.dart.weak.transformed.expect
index 32a8f57..631f443 100644
--- a/pkg/front_end/testcases/nnbd/platform_definite_assignment/main.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/platform_definite_assignment/main.dart.weak.transformed.expect
@@ -52,7 +52,7 @@
 import "dart:_internal";
 
 @#C1
-class Class<T extends core::num = core::num> extends core::Object /*hasConstConstructor*/  {
+class Class<T extends core::num> extends core::Object /*hasConstConstructor*/  {
   final field core::int a;
   final field test::Class::T b;
   const constructor constConstructor(core::int a, test::Class::T b) → test::Class<test::Class::T>
diff --git a/pkg/front_end/testcases/nnbd/potentially_constant_type_as.dart.strong.expect b/pkg/front_end/testcases/nnbd/potentially_constant_type_as.dart.strong.expect
index d067529..5612a60 100644
--- a/pkg/front_end/testcases/nnbd/potentially_constant_type_as.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/potentially_constant_type_as.dart.strong.expect
@@ -143,7 +143,7 @@
     : self::Class::field = value as{ForNonNullableByDefault} self::Class::T%, super core::Object::•()
     ;
 }
-class ClassWithBound<T extends core::num = core::num> extends core::Object /*hasConstConstructor*/  {
+class ClassWithBound<T extends core::num> extends core::Object /*hasConstConstructor*/  {
   final field self::ClassWithBound::T field;
   const constructor •() → self::ClassWithBound<self::ClassWithBound::T>
     : self::ClassWithBound::field = (#C1) as{ForNonNullableByDefault} self::ClassWithBound::T, super core::Object::•()
diff --git a/pkg/front_end/testcases/nnbd/potentially_constant_type_as.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/potentially_constant_type_as.dart.strong.transformed.expect
index d067529..5612a60 100644
--- a/pkg/front_end/testcases/nnbd/potentially_constant_type_as.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/potentially_constant_type_as.dart.strong.transformed.expect
@@ -143,7 +143,7 @@
     : self::Class::field = value as{ForNonNullableByDefault} self::Class::T%, super core::Object::•()
     ;
 }
-class ClassWithBound<T extends core::num = core::num> extends core::Object /*hasConstConstructor*/  {
+class ClassWithBound<T extends core::num> extends core::Object /*hasConstConstructor*/  {
   final field self::ClassWithBound::T field;
   const constructor •() → self::ClassWithBound<self::ClassWithBound::T>
     : self::ClassWithBound::field = (#C1) as{ForNonNullableByDefault} self::ClassWithBound::T, super core::Object::•()
diff --git a/pkg/front_end/testcases/nnbd/potentially_constant_type_as.dart.weak.expect b/pkg/front_end/testcases/nnbd/potentially_constant_type_as.dart.weak.expect
index 9abe043..ff4ef6e 100644
--- a/pkg/front_end/testcases/nnbd/potentially_constant_type_as.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/potentially_constant_type_as.dart.weak.expect
@@ -135,7 +135,7 @@
     : self::Class::field = value as{ForNonNullableByDefault} self::Class::T%, super core::Object::•()
     ;
 }
-class ClassWithBound<T extends core::num = core::num> extends core::Object /*hasConstConstructor*/  {
+class ClassWithBound<T extends core::num> extends core::Object /*hasConstConstructor*/  {
   final field self::ClassWithBound::T field;
   const constructor •() → self::ClassWithBound<self::ClassWithBound::T>
     : self::ClassWithBound::field = (#C1) as{ForNonNullableByDefault} self::ClassWithBound::T, super core::Object::•()
diff --git a/pkg/front_end/testcases/nnbd/potentially_constant_type_as.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/potentially_constant_type_as.dart.weak.outline.expect
index 391e7e9..b3e41d5 100644
--- a/pkg/front_end/testcases/nnbd/potentially_constant_type_as.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/potentially_constant_type_as.dart.weak.outline.expect
@@ -8,7 +8,7 @@
     : self::Class::field = value as{ForNonNullableByDefault} self::Class::T%, super core::Object::•()
     ;
 }
-class ClassWithBound<T extends core::num = core::num> extends core::Object /*hasConstConstructor*/  {
+class ClassWithBound<T extends core::num> extends core::Object /*hasConstConstructor*/  {
   final field self::ClassWithBound::T field;
   const constructor •() → self::ClassWithBound<self::ClassWithBound::T>
     : self::ClassWithBound::field = self::three as{ForNonNullableByDefault} self::ClassWithBound::T, super core::Object::•()
diff --git a/pkg/front_end/testcases/nnbd/potentially_constant_type_as.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/potentially_constant_type_as.dart.weak.transformed.expect
index 9abe043..ff4ef6e 100644
--- a/pkg/front_end/testcases/nnbd/potentially_constant_type_as.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/potentially_constant_type_as.dart.weak.transformed.expect
@@ -135,7 +135,7 @@
     : self::Class::field = value as{ForNonNullableByDefault} self::Class::T%, super core::Object::•()
     ;
 }
-class ClassWithBound<T extends core::num = core::num> extends core::Object /*hasConstConstructor*/  {
+class ClassWithBound<T extends core::num> extends core::Object /*hasConstConstructor*/  {
   final field self::ClassWithBound::T field;
   const constructor •() → self::ClassWithBound<self::ClassWithBound::T>
     : self::ClassWithBound::field = (#C1) as{ForNonNullableByDefault} self::ClassWithBound::T, super core::Object::•()
diff --git a/pkg/front_end/testcases/nnbd/potentially_constant_type_is.dart.strong.expect b/pkg/front_end/testcases/nnbd/potentially_constant_type_is.dart.strong.expect
index dd71e24..c131260 100644
--- a/pkg/front_end/testcases/nnbd/potentially_constant_type_is.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/potentially_constant_type_is.dart.strong.expect
@@ -8,7 +8,7 @@
     : self::Class::field = value is{ForNonNullableByDefault} self::Class::T%, super core::Object::•()
     ;
 }
-class ClassWithBound<T extends core::num = core::num> extends core::Object /*hasConstConstructor*/  {
+class ClassWithBound<T extends core::num> extends core::Object /*hasConstConstructor*/  {
   final field core::bool field;
   const constructor •() → self::ClassWithBound<self::ClassWithBound::T>
     : self::ClassWithBound::field = (#C1) is{ForNonNullableByDefault} self::ClassWithBound::T, super core::Object::•()
diff --git a/pkg/front_end/testcases/nnbd/potentially_constant_type_is.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/potentially_constant_type_is.dart.strong.transformed.expect
index dd71e24..c131260 100644
--- a/pkg/front_end/testcases/nnbd/potentially_constant_type_is.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/potentially_constant_type_is.dart.strong.transformed.expect
@@ -8,7 +8,7 @@
     : self::Class::field = value is{ForNonNullableByDefault} self::Class::T%, super core::Object::•()
     ;
 }
-class ClassWithBound<T extends core::num = core::num> extends core::Object /*hasConstConstructor*/  {
+class ClassWithBound<T extends core::num> extends core::Object /*hasConstConstructor*/  {
   final field core::bool field;
   const constructor •() → self::ClassWithBound<self::ClassWithBound::T>
     : self::ClassWithBound::field = (#C1) is{ForNonNullableByDefault} self::ClassWithBound::T, super core::Object::•()
diff --git a/pkg/front_end/testcases/nnbd/potentially_constant_type_is.dart.weak.expect b/pkg/front_end/testcases/nnbd/potentially_constant_type_is.dart.weak.expect
index da6412f..d959fa2 100644
--- a/pkg/front_end/testcases/nnbd/potentially_constant_type_is.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/potentially_constant_type_is.dart.weak.expect
@@ -8,7 +8,7 @@
     : self::Class::field = value is{ForNonNullableByDefault} self::Class::T%, super core::Object::•()
     ;
 }
-class ClassWithBound<T extends core::num = core::num> extends core::Object /*hasConstConstructor*/  {
+class ClassWithBound<T extends core::num> extends core::Object /*hasConstConstructor*/  {
   final field core::bool field;
   const constructor •() → self::ClassWithBound<self::ClassWithBound::T>
     : self::ClassWithBound::field = (#C1) is{ForNonNullableByDefault} self::ClassWithBound::T, super core::Object::•()
diff --git a/pkg/front_end/testcases/nnbd/potentially_constant_type_is.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/potentially_constant_type_is.dart.weak.outline.expect
index 90a132b..ba55100 100644
--- a/pkg/front_end/testcases/nnbd/potentially_constant_type_is.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/potentially_constant_type_is.dart.weak.outline.expect
@@ -8,7 +8,7 @@
     : self::Class::field = value is{ForNonNullableByDefault} self::Class::T%, super core::Object::•()
     ;
 }
-class ClassWithBound<T extends core::num = core::num> extends core::Object /*hasConstConstructor*/  {
+class ClassWithBound<T extends core::num> extends core::Object /*hasConstConstructor*/  {
   final field core::bool field;
   const constructor •() → self::ClassWithBound<self::ClassWithBound::T>
     : self::ClassWithBound::field = self::three is{ForNonNullableByDefault} self::ClassWithBound::T, super core::Object::•()
diff --git a/pkg/front_end/testcases/nnbd/potentially_constant_type_is.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/potentially_constant_type_is.dart.weak.transformed.expect
index da6412f..d959fa2 100644
--- a/pkg/front_end/testcases/nnbd/potentially_constant_type_is.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/potentially_constant_type_is.dart.weak.transformed.expect
@@ -8,7 +8,7 @@
     : self::Class::field = value is{ForNonNullableByDefault} self::Class::T%, super core::Object::•()
     ;
 }
-class ClassWithBound<T extends core::num = core::num> extends core::Object /*hasConstConstructor*/  {
+class ClassWithBound<T extends core::num> extends core::Object /*hasConstConstructor*/  {
   final field core::bool field;
   const constructor •() → self::ClassWithBound<self::ClassWithBound::T>
     : self::ClassWithBound::field = (#C1) is{ForNonNullableByDefault} self::ClassWithBound::T, super core::Object::•()
diff --git a/pkg/front_end/testcases/nnbd/potentially_non_nullable_field.dart.strong.expect b/pkg/front_end/testcases/nnbd/potentially_non_nullable_field.dart.strong.expect
index ac1c56b..a39f6c2 100644
--- a/pkg/front_end/testcases/nnbd/potentially_non_nullable_field.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/potentially_non_nullable_field.dart.strong.expect
@@ -21,7 +21,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::Object? = core::Object?> extends core::Object {
+class A<T extends core::Object?> extends core::Object {
   static field core::int x = null;
   static field core::int? y = null;
   late static field core::int z;
diff --git a/pkg/front_end/testcases/nnbd/potentially_non_nullable_field.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/potentially_non_nullable_field.dart.strong.transformed.expect
index ac1c56b..a39f6c2 100644
--- a/pkg/front_end/testcases/nnbd/potentially_non_nullable_field.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/potentially_non_nullable_field.dart.strong.transformed.expect
@@ -21,7 +21,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::Object? = core::Object?> extends core::Object {
+class A<T extends core::Object?> extends core::Object {
   static field core::int x = null;
   static field core::int? y = null;
   late static field core::int z;
diff --git a/pkg/front_end/testcases/nnbd/potentially_non_nullable_field.dart.weak.expect b/pkg/front_end/testcases/nnbd/potentially_non_nullable_field.dart.weak.expect
index ac1c56b..a39f6c2 100644
--- a/pkg/front_end/testcases/nnbd/potentially_non_nullable_field.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/potentially_non_nullable_field.dart.weak.expect
@@ -21,7 +21,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::Object? = core::Object?> extends core::Object {
+class A<T extends core::Object?> extends core::Object {
   static field core::int x = null;
   static field core::int? y = null;
   late static field core::int z;
diff --git a/pkg/front_end/testcases/nnbd/potentially_non_nullable_field.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/potentially_non_nullable_field.dart.weak.outline.expect
index 5f5e178..088b4c8 100644
--- a/pkg/front_end/testcases/nnbd/potentially_non_nullable_field.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/potentially_non_nullable_field.dart.weak.outline.expect
@@ -13,7 +13,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::Object? = core::Object?> extends core::Object {
+class A<T extends core::Object?> extends core::Object {
   static field core::int x;
   static field core::int? y;
   late static field core::int z;
diff --git a/pkg/front_end/testcases/nnbd/potentially_non_nullable_field.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/potentially_non_nullable_field.dart.weak.transformed.expect
index ac1c56b..a39f6c2 100644
--- a/pkg/front_end/testcases/nnbd/potentially_non_nullable_field.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/potentially_non_nullable_field.dart.weak.transformed.expect
@@ -21,7 +21,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::Object? = core::Object?> extends core::Object {
+class A<T extends core::Object?> extends core::Object {
   static field core::int x = null;
   static field core::int? y = null;
   late static field core::int z;
diff --git a/pkg/front_end/testcases/nnbd/substitution_in_inference.dart.strong.expect b/pkg/front_end/testcases/nnbd/substitution_in_inference.dart.strong.expect
index afd873e..7dda588 100644
--- a/pkg/front_end/testcases/nnbd/substitution_in_inference.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/substitution_in_inference.dart.strong.expect
@@ -2,20 +2,20 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::Object? = core::Object?, S extends core::Object = core::Object> extends core::Object {
+class A<T extends core::Object?, S extends core::Object> extends core::Object {
   synthetic constructor •() → self::A<self::A::T%, self::A::S>
     : super core::Object::•()
     ;
-  method hest<generic-covariant-impl X extends self::A::T% = self::A::T%, Y extends core::List<self::A::hest::X%> = core::List<self::A::T%>, Z extends core::List<self::A::hest::X?> = core::List<self::A::T?>>() → dynamic
+  method hest<generic-covariant-impl X extends self::A::T%, Y extends core::List<self::A::hest::X%> = core::List<self::A::T%>, Z extends core::List<self::A::hest::X?> = core::List<self::A::T?>>() → dynamic
     return null;
-  method fisk<generic-covariant-impl X extends self::A::S = self::A::S, Y extends core::List<self::A::fisk::X> = core::List<self::A::S>, Z extends core::List<self::A::fisk::X?> = core::List<self::A::S?>>() → dynamic
+  method fisk<generic-covariant-impl X extends self::A::S, Y extends core::List<self::A::fisk::X> = core::List<self::A::S>, Z extends core::List<self::A::fisk::X?> = core::List<self::A::S?>>() → dynamic
     return null;
-  method mus<X extends core::Object? = core::Object?, Y extends core::List<self::A::mus::X%> = core::List<core::Object?>, Z extends core::List<self::A::mus::X?> = core::List<core::Object?>>() → dynamic
+  method mus<X extends core::Object?, Y extends core::List<self::A::mus::X%> = core::List<core::Object?>, Z extends core::List<self::A::mus::X?> = core::List<core::Object?>>() → dynamic
     return null;
 }
-static method foo<T extends core::Object? = core::Object?, S extends core::List<self::foo::T%> = core::List<core::Object?>>(self::foo::T% t) → dynamic
+static method foo<T extends core::Object?, S extends core::List<self::foo::T%> = core::List<core::Object?>>(self::foo::T% t) → dynamic
   return null;
-static method bar<T extends core::Object? = core::Object?, S extends core::List<self::bar::T?> = core::List<core::Object?>>(self::bar::T% t) → dynamic
+static method bar<T extends core::Object?, S extends core::List<self::bar::T?> = core::List<core::Object?>>(self::bar::T% t) → dynamic
   return null;
 static method baz(core::int? x, core::int y) → dynamic {
   self::foo<core::int?, core::List<core::int?>>(x);
diff --git a/pkg/front_end/testcases/nnbd/substitution_in_inference.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/substitution_in_inference.dart.strong.transformed.expect
index afd873e..7dda588 100644
--- a/pkg/front_end/testcases/nnbd/substitution_in_inference.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/substitution_in_inference.dart.strong.transformed.expect
@@ -2,20 +2,20 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::Object? = core::Object?, S extends core::Object = core::Object> extends core::Object {
+class A<T extends core::Object?, S extends core::Object> extends core::Object {
   synthetic constructor •() → self::A<self::A::T%, self::A::S>
     : super core::Object::•()
     ;
-  method hest<generic-covariant-impl X extends self::A::T% = self::A::T%, Y extends core::List<self::A::hest::X%> = core::List<self::A::T%>, Z extends core::List<self::A::hest::X?> = core::List<self::A::T?>>() → dynamic
+  method hest<generic-covariant-impl X extends self::A::T%, Y extends core::List<self::A::hest::X%> = core::List<self::A::T%>, Z extends core::List<self::A::hest::X?> = core::List<self::A::T?>>() → dynamic
     return null;
-  method fisk<generic-covariant-impl X extends self::A::S = self::A::S, Y extends core::List<self::A::fisk::X> = core::List<self::A::S>, Z extends core::List<self::A::fisk::X?> = core::List<self::A::S?>>() → dynamic
+  method fisk<generic-covariant-impl X extends self::A::S, Y extends core::List<self::A::fisk::X> = core::List<self::A::S>, Z extends core::List<self::A::fisk::X?> = core::List<self::A::S?>>() → dynamic
     return null;
-  method mus<X extends core::Object? = core::Object?, Y extends core::List<self::A::mus::X%> = core::List<core::Object?>, Z extends core::List<self::A::mus::X?> = core::List<core::Object?>>() → dynamic
+  method mus<X extends core::Object?, Y extends core::List<self::A::mus::X%> = core::List<core::Object?>, Z extends core::List<self::A::mus::X?> = core::List<core::Object?>>() → dynamic
     return null;
 }
-static method foo<T extends core::Object? = core::Object?, S extends core::List<self::foo::T%> = core::List<core::Object?>>(self::foo::T% t) → dynamic
+static method foo<T extends core::Object?, S extends core::List<self::foo::T%> = core::List<core::Object?>>(self::foo::T% t) → dynamic
   return null;
-static method bar<T extends core::Object? = core::Object?, S extends core::List<self::bar::T?> = core::List<core::Object?>>(self::bar::T% t) → dynamic
+static method bar<T extends core::Object?, S extends core::List<self::bar::T?> = core::List<core::Object?>>(self::bar::T% t) → dynamic
   return null;
 static method baz(core::int? x, core::int y) → dynamic {
   self::foo<core::int?, core::List<core::int?>>(x);
diff --git a/pkg/front_end/testcases/nnbd/substitution_in_inference.dart.weak.expect b/pkg/front_end/testcases/nnbd/substitution_in_inference.dart.weak.expect
index afd873e..7dda588 100644
--- a/pkg/front_end/testcases/nnbd/substitution_in_inference.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/substitution_in_inference.dart.weak.expect
@@ -2,20 +2,20 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::Object? = core::Object?, S extends core::Object = core::Object> extends core::Object {
+class A<T extends core::Object?, S extends core::Object> extends core::Object {
   synthetic constructor •() → self::A<self::A::T%, self::A::S>
     : super core::Object::•()
     ;
-  method hest<generic-covariant-impl X extends self::A::T% = self::A::T%, Y extends core::List<self::A::hest::X%> = core::List<self::A::T%>, Z extends core::List<self::A::hest::X?> = core::List<self::A::T?>>() → dynamic
+  method hest<generic-covariant-impl X extends self::A::T%, Y extends core::List<self::A::hest::X%> = core::List<self::A::T%>, Z extends core::List<self::A::hest::X?> = core::List<self::A::T?>>() → dynamic
     return null;
-  method fisk<generic-covariant-impl X extends self::A::S = self::A::S, Y extends core::List<self::A::fisk::X> = core::List<self::A::S>, Z extends core::List<self::A::fisk::X?> = core::List<self::A::S?>>() → dynamic
+  method fisk<generic-covariant-impl X extends self::A::S, Y extends core::List<self::A::fisk::X> = core::List<self::A::S>, Z extends core::List<self::A::fisk::X?> = core::List<self::A::S?>>() → dynamic
     return null;
-  method mus<X extends core::Object? = core::Object?, Y extends core::List<self::A::mus::X%> = core::List<core::Object?>, Z extends core::List<self::A::mus::X?> = core::List<core::Object?>>() → dynamic
+  method mus<X extends core::Object?, Y extends core::List<self::A::mus::X%> = core::List<core::Object?>, Z extends core::List<self::A::mus::X?> = core::List<core::Object?>>() → dynamic
     return null;
 }
-static method foo<T extends core::Object? = core::Object?, S extends core::List<self::foo::T%> = core::List<core::Object?>>(self::foo::T% t) → dynamic
+static method foo<T extends core::Object?, S extends core::List<self::foo::T%> = core::List<core::Object?>>(self::foo::T% t) → dynamic
   return null;
-static method bar<T extends core::Object? = core::Object?, S extends core::List<self::bar::T?> = core::List<core::Object?>>(self::bar::T% t) → dynamic
+static method bar<T extends core::Object?, S extends core::List<self::bar::T?> = core::List<core::Object?>>(self::bar::T% t) → dynamic
   return null;
 static method baz(core::int? x, core::int y) → dynamic {
   self::foo<core::int?, core::List<core::int?>>(x);
diff --git a/pkg/front_end/testcases/nnbd/substitution_in_inference.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/substitution_in_inference.dart.weak.outline.expect
index afffc19..091ebb6 100644
--- a/pkg/front_end/testcases/nnbd/substitution_in_inference.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/substitution_in_inference.dart.weak.outline.expect
@@ -2,19 +2,19 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::Object? = core::Object?, S extends core::Object = core::Object> extends core::Object {
+class A<T extends core::Object?, S extends core::Object> extends core::Object {
   synthetic constructor •() → self::A<self::A::T%, self::A::S>
     ;
-  method hest<generic-covariant-impl X extends self::A::T% = self::A::T%, Y extends core::List<self::A::hest::X%> = core::List<self::A::T%>, Z extends core::List<self::A::hest::X?> = core::List<self::A::T?>>() → dynamic
+  method hest<generic-covariant-impl X extends self::A::T%, Y extends core::List<self::A::hest::X%> = core::List<self::A::T%>, Z extends core::List<self::A::hest::X?> = core::List<self::A::T?>>() → dynamic
     ;
-  method fisk<generic-covariant-impl X extends self::A::S = self::A::S, Y extends core::List<self::A::fisk::X> = core::List<self::A::S>, Z extends core::List<self::A::fisk::X?> = core::List<self::A::S?>>() → dynamic
+  method fisk<generic-covariant-impl X extends self::A::S, Y extends core::List<self::A::fisk::X> = core::List<self::A::S>, Z extends core::List<self::A::fisk::X?> = core::List<self::A::S?>>() → dynamic
     ;
-  method mus<X extends core::Object? = core::Object?, Y extends core::List<self::A::mus::X%> = core::List<core::Object?>, Z extends core::List<self::A::mus::X?> = core::List<core::Object?>>() → dynamic
+  method mus<X extends core::Object?, Y extends core::List<self::A::mus::X%> = core::List<core::Object?>, Z extends core::List<self::A::mus::X?> = core::List<core::Object?>>() → dynamic
     ;
 }
-static method foo<T extends core::Object? = core::Object?, S extends core::List<self::foo::T%> = core::List<core::Object?>>(self::foo::T% t) → dynamic
+static method foo<T extends core::Object?, S extends core::List<self::foo::T%> = core::List<core::Object?>>(self::foo::T% t) → dynamic
   ;
-static method bar<T extends core::Object? = core::Object?, S extends core::List<self::bar::T?> = core::List<core::Object?>>(self::bar::T% t) → dynamic
+static method bar<T extends core::Object?, S extends core::List<self::bar::T?> = core::List<core::Object?>>(self::bar::T% t) → dynamic
   ;
 static method baz(core::int? x, core::int y) → dynamic
   ;
diff --git a/pkg/front_end/testcases/nnbd/substitution_in_inference.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/substitution_in_inference.dart.weak.transformed.expect
index afd873e..7dda588 100644
--- a/pkg/front_end/testcases/nnbd/substitution_in_inference.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/substitution_in_inference.dart.weak.transformed.expect
@@ -2,20 +2,20 @@
 import self as self;
 import "dart:core" as core;
 
-class A<T extends core::Object? = core::Object?, S extends core::Object = core::Object> extends core::Object {
+class A<T extends core::Object?, S extends core::Object> extends core::Object {
   synthetic constructor •() → self::A<self::A::T%, self::A::S>
     : super core::Object::•()
     ;
-  method hest<generic-covariant-impl X extends self::A::T% = self::A::T%, Y extends core::List<self::A::hest::X%> = core::List<self::A::T%>, Z extends core::List<self::A::hest::X?> = core::List<self::A::T?>>() → dynamic
+  method hest<generic-covariant-impl X extends self::A::T%, Y extends core::List<self::A::hest::X%> = core::List<self::A::T%>, Z extends core::List<self::A::hest::X?> = core::List<self::A::T?>>() → dynamic
     return null;
-  method fisk<generic-covariant-impl X extends self::A::S = self::A::S, Y extends core::List<self::A::fisk::X> = core::List<self::A::S>, Z extends core::List<self::A::fisk::X?> = core::List<self::A::S?>>() → dynamic
+  method fisk<generic-covariant-impl X extends self::A::S, Y extends core::List<self::A::fisk::X> = core::List<self::A::S>, Z extends core::List<self::A::fisk::X?> = core::List<self::A::S?>>() → dynamic
     return null;
-  method mus<X extends core::Object? = core::Object?, Y extends core::List<self::A::mus::X%> = core::List<core::Object?>, Z extends core::List<self::A::mus::X?> = core::List<core::Object?>>() → dynamic
+  method mus<X extends core::Object?, Y extends core::List<self::A::mus::X%> = core::List<core::Object?>, Z extends core::List<self::A::mus::X?> = core::List<core::Object?>>() → dynamic
     return null;
 }
-static method foo<T extends core::Object? = core::Object?, S extends core::List<self::foo::T%> = core::List<core::Object?>>(self::foo::T% t) → dynamic
+static method foo<T extends core::Object?, S extends core::List<self::foo::T%> = core::List<core::Object?>>(self::foo::T% t) → dynamic
   return null;
-static method bar<T extends core::Object? = core::Object?, S extends core::List<self::bar::T?> = core::List<core::Object?>>(self::bar::T% t) → dynamic
+static method bar<T extends core::Object?, S extends core::List<self::bar::T?> = core::List<core::Object?>>(self::bar::T% t) → dynamic
   return null;
 static method baz(core::int? x, core::int y) → dynamic {
   self::foo<core::int?, core::List<core::int?>>(x);
diff --git a/pkg/front_end/testcases/nnbd/super_bounded_hint.dart.strong.expect b/pkg/front_end/testcases/nnbd/super_bounded_hint.dart.strong.expect
index 98725b8..5537cc3 100644
--- a/pkg/front_end/testcases/nnbd/super_bounded_hint.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/super_bounded_hint.dart.strong.expect
@@ -533,7 +533,7 @@
     : super core::Object::•()
     ;
 }
-class Foo3a<X extends (self::A<Never>) → self::A<dynamic> = (self::A<Never>) → self::A<dynamic>> extends core::Object {
+class Foo3a<X extends (self::A<Never>) → self::A<dynamic>> extends core::Object {
   synthetic constructor •() → self::Foo3a<self::Foo3a::X>
     : super core::Object::•()
     ;
@@ -543,12 +543,12 @@
     : super core::Object::•()
     ;
 }
-class B<X extends core::int = core::int> extends core::Object {
+class B<X extends core::int> extends core::Object {
   synthetic constructor •() → self::B<self::B::X>
     : super core::Object::•()
     ;
 }
-class Bar3<X extends self::B<core::num> = self::B<core::num>> extends core::Object {
+class Bar3<X extends self::B<core::num>> extends core::Object {
   synthetic constructor •() → self::Bar3<self::Bar3::X>
     : super core::Object::•()
     ;
@@ -560,7 +560,7 @@
 }
 static method foo1a((self::A<Never>) → self::A<dynamic> x) → dynamic {}
 static method foo1b((self::A<Never>) → self::A<dynamic> x) → dynamic {}
-static method foo2a<X extends (self::A<Never>) → self::A<dynamic> = (self::A<Never>) → self::A<dynamic>>() → dynamic {}
+static method foo2a<X extends (self::A<Never>) → self::A<dynamic>>() → dynamic {}
 static method foo2b<X extends (self::A<Never>) → self::A<dynamic> = dynamic>() → dynamic {}
 static method foo4a() → (self::A<Never>) → self::A<dynamic>
   return throw 42;
@@ -573,7 +573,7 @@
   for ((self::A<Never>) → self::A<dynamic> x in <(self::A<Never>) → self::A<dynamic>>[]) {
   }
   function fooFoo1((self::A<Never>) → self::A<dynamic> x) → Null {}
-  function fooFoo2<X extends (self::A<Never>) → self::A<dynamic> = (self::A<Never>) → self::A<dynamic>>() → Null {}
+  function fooFoo2<X extends (self::A<Never>) → self::A<dynamic>>() → Null {}
   function fooFoo4() → (self::A<Never>) → self::A<dynamic>
     return throw 42;
   function fooFoo5({required (self::A<Never>) → self::A<dynamic> x = #C1}) → Null {}
@@ -584,7 +584,7 @@
   for ((self::A<Never>) → self::A<dynamic> x in <(self::A<Never>) → self::A<dynamic>>[]) {
   }
   function fooFoo1((self::A<Never>) → self::A<dynamic> x) → Null {}
-  function fooFoo2<X extends (self::A<Never>) → self::A<dynamic> = (self::A<Never>) → self::A<dynamic>>() → Null {}
+  function fooFoo2<X extends (self::A<Never>) → self::A<dynamic>>() → Null {}
   function fooFoo4() → (self::A<Never>) → self::A<dynamic>
     return throw 42;
   function fooFoo5({required (self::A<Never>) → self::A<dynamic> x = #C1}) → Null {}
@@ -593,7 +593,7 @@
 static method foo7a([(self::A<Never>) →? self::A<dynamic> x = #C1]) → dynamic {}
 static method foo7b([(self::A<Never>) →? self::A<dynamic> x = #C1]) → dynamic {}
 static method bar1(self::B<core::num> x) → dynamic {}
-static method bar2<X extends self::B<core::num> = self::B<core::num>>() → dynamic {}
+static method bar2<X extends self::B<core::num>>() → dynamic {}
 static method bar4() → self::B<core::num>
   return throw 42;
 static method bar5({required self::B<core::num> x = #C1}) → dynamic {}
@@ -602,7 +602,7 @@
   for (self::B<core::num> x in <self::B<core::num>>[]) {
   }
   function barBar1(self::B<core::num> x) → Null {}
-  function barBar2<X extends self::B<core::num> = self::B<core::num>>() → Null {}
+  function barBar2<X extends self::B<core::num>>() → Null {}
   function barBar4() → self::B<core::num>
     return throw 42;
   function barBar5({required self::B<core::num> x = #C1}) → Null {}
diff --git a/pkg/front_end/testcases/nnbd/super_bounded_hint.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/super_bounded_hint.dart.strong.transformed.expect
index edb2e83..3a904fc 100644
--- a/pkg/front_end/testcases/nnbd/super_bounded_hint.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/super_bounded_hint.dart.strong.transformed.expect
@@ -533,7 +533,7 @@
     : super core::Object::•()
     ;
 }
-class Foo3a<X extends (self::A<Never>) → self::A<dynamic> = (self::A<Never>) → self::A<dynamic>> extends core::Object {
+class Foo3a<X extends (self::A<Never>) → self::A<dynamic>> extends core::Object {
   synthetic constructor •() → self::Foo3a<self::Foo3a::X>
     : super core::Object::•()
     ;
@@ -543,12 +543,12 @@
     : super core::Object::•()
     ;
 }
-class B<X extends core::int = core::int> extends core::Object {
+class B<X extends core::int> extends core::Object {
   synthetic constructor •() → self::B<self::B::X>
     : super core::Object::•()
     ;
 }
-class Bar3<X extends self::B<core::num> = self::B<core::num>> extends core::Object {
+class Bar3<X extends self::B<core::num>> extends core::Object {
   synthetic constructor •() → self::Bar3<self::Bar3::X>
     : super core::Object::•()
     ;
@@ -560,7 +560,7 @@
 }
 static method foo1a((self::A<Never>) → self::A<dynamic> x) → dynamic {}
 static method foo1b((self::A<Never>) → self::A<dynamic> x) → dynamic {}
-static method foo2a<X extends (self::A<Never>) → self::A<dynamic> = (self::A<Never>) → self::A<dynamic>>() → dynamic {}
+static method foo2a<X extends (self::A<Never>) → self::A<dynamic>>() → dynamic {}
 static method foo2b<X extends (self::A<Never>) → self::A<dynamic> = dynamic>() → dynamic {}
 static method foo4a() → (self::A<Never>) → self::A<dynamic>
   return throw 42;
@@ -578,7 +578,7 @@
     }
   }
   function fooFoo1((self::A<Never>) → self::A<dynamic> x) → Null {}
-  function fooFoo2<X extends (self::A<Never>) → self::A<dynamic> = (self::A<Never>) → self::A<dynamic>>() → Null {}
+  function fooFoo2<X extends (self::A<Never>) → self::A<dynamic>>() → Null {}
   function fooFoo4() → (self::A<Never>) → self::A<dynamic>
     return throw 42;
   function fooFoo5({required (self::A<Never>) → self::A<dynamic> x = #C1}) → Null {}
@@ -594,7 +594,7 @@
     }
   }
   function fooFoo1((self::A<Never>) → self::A<dynamic> x) → Null {}
-  function fooFoo2<X extends (self::A<Never>) → self::A<dynamic> = (self::A<Never>) → self::A<dynamic>>() → Null {}
+  function fooFoo2<X extends (self::A<Never>) → self::A<dynamic>>() → Null {}
   function fooFoo4() → (self::A<Never>) → self::A<dynamic>
     return throw 42;
   function fooFoo5({required (self::A<Never>) → self::A<dynamic> x = #C1}) → Null {}
@@ -603,7 +603,7 @@
 static method foo7a([(self::A<Never>) →? self::A<dynamic> x = #C1]) → dynamic {}
 static method foo7b([(self::A<Never>) →? self::A<dynamic> x = #C1]) → dynamic {}
 static method bar1(self::B<core::num> x) → dynamic {}
-static method bar2<X extends self::B<core::num> = self::B<core::num>>() → dynamic {}
+static method bar2<X extends self::B<core::num>>() → dynamic {}
 static method bar4() → self::B<core::num>
   return throw 42;
 static method bar5({required self::B<core::num> x = #C1}) → dynamic {}
@@ -617,7 +617,7 @@
     }
   }
   function barBar1(self::B<core::num> x) → Null {}
-  function barBar2<X extends self::B<core::num> = self::B<core::num>>() → Null {}
+  function barBar2<X extends self::B<core::num>>() → Null {}
   function barBar4() → self::B<core::num>
     return throw 42;
   function barBar5({required self::B<core::num> x = #C1}) → Null {}
diff --git a/pkg/front_end/testcases/nnbd/super_bounded_hint.dart.weak.expect b/pkg/front_end/testcases/nnbd/super_bounded_hint.dart.weak.expect
index 98725b8..5537cc3 100644
--- a/pkg/front_end/testcases/nnbd/super_bounded_hint.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/super_bounded_hint.dart.weak.expect
@@ -533,7 +533,7 @@
     : super core::Object::•()
     ;
 }
-class Foo3a<X extends (self::A<Never>) → self::A<dynamic> = (self::A<Never>) → self::A<dynamic>> extends core::Object {
+class Foo3a<X extends (self::A<Never>) → self::A<dynamic>> extends core::Object {
   synthetic constructor •() → self::Foo3a<self::Foo3a::X>
     : super core::Object::•()
     ;
@@ -543,12 +543,12 @@
     : super core::Object::•()
     ;
 }
-class B<X extends core::int = core::int> extends core::Object {
+class B<X extends core::int> extends core::Object {
   synthetic constructor •() → self::B<self::B::X>
     : super core::Object::•()
     ;
 }
-class Bar3<X extends self::B<core::num> = self::B<core::num>> extends core::Object {
+class Bar3<X extends self::B<core::num>> extends core::Object {
   synthetic constructor •() → self::Bar3<self::Bar3::X>
     : super core::Object::•()
     ;
@@ -560,7 +560,7 @@
 }
 static method foo1a((self::A<Never>) → self::A<dynamic> x) → dynamic {}
 static method foo1b((self::A<Never>) → self::A<dynamic> x) → dynamic {}
-static method foo2a<X extends (self::A<Never>) → self::A<dynamic> = (self::A<Never>) → self::A<dynamic>>() → dynamic {}
+static method foo2a<X extends (self::A<Never>) → self::A<dynamic>>() → dynamic {}
 static method foo2b<X extends (self::A<Never>) → self::A<dynamic> = dynamic>() → dynamic {}
 static method foo4a() → (self::A<Never>) → self::A<dynamic>
   return throw 42;
@@ -573,7 +573,7 @@
   for ((self::A<Never>) → self::A<dynamic> x in <(self::A<Never>) → self::A<dynamic>>[]) {
   }
   function fooFoo1((self::A<Never>) → self::A<dynamic> x) → Null {}
-  function fooFoo2<X extends (self::A<Never>) → self::A<dynamic> = (self::A<Never>) → self::A<dynamic>>() → Null {}
+  function fooFoo2<X extends (self::A<Never>) → self::A<dynamic>>() → Null {}
   function fooFoo4() → (self::A<Never>) → self::A<dynamic>
     return throw 42;
   function fooFoo5({required (self::A<Never>) → self::A<dynamic> x = #C1}) → Null {}
@@ -584,7 +584,7 @@
   for ((self::A<Never>) → self::A<dynamic> x in <(self::A<Never>) → self::A<dynamic>>[]) {
   }
   function fooFoo1((self::A<Never>) → self::A<dynamic> x) → Null {}
-  function fooFoo2<X extends (self::A<Never>) → self::A<dynamic> = (self::A<Never>) → self::A<dynamic>>() → Null {}
+  function fooFoo2<X extends (self::A<Never>) → self::A<dynamic>>() → Null {}
   function fooFoo4() → (self::A<Never>) → self::A<dynamic>
     return throw 42;
   function fooFoo5({required (self::A<Never>) → self::A<dynamic> x = #C1}) → Null {}
@@ -593,7 +593,7 @@
 static method foo7a([(self::A<Never>) →? self::A<dynamic> x = #C1]) → dynamic {}
 static method foo7b([(self::A<Never>) →? self::A<dynamic> x = #C1]) → dynamic {}
 static method bar1(self::B<core::num> x) → dynamic {}
-static method bar2<X extends self::B<core::num> = self::B<core::num>>() → dynamic {}
+static method bar2<X extends self::B<core::num>>() → dynamic {}
 static method bar4() → self::B<core::num>
   return throw 42;
 static method bar5({required self::B<core::num> x = #C1}) → dynamic {}
@@ -602,7 +602,7 @@
   for (self::B<core::num> x in <self::B<core::num>>[]) {
   }
   function barBar1(self::B<core::num> x) → Null {}
-  function barBar2<X extends self::B<core::num> = self::B<core::num>>() → Null {}
+  function barBar2<X extends self::B<core::num>>() → Null {}
   function barBar4() → self::B<core::num>
     return throw 42;
   function barBar5({required self::B<core::num> x = #C1}) → Null {}
diff --git a/pkg/front_end/testcases/nnbd/super_bounded_hint.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/super_bounded_hint.dart.weak.outline.expect
index 1d220b5..155fe0cd 100644
--- a/pkg/front_end/testcases/nnbd/super_bounded_hint.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/super_bounded_hint.dart.weak.outline.expect
@@ -236,7 +236,7 @@
   synthetic constructor •() → self::A<self::A::X%>
     ;
 }
-class Foo3a<X extends (self::A<Never>) → self::A<dynamic> = (self::A<Never>) → self::A<dynamic>> extends core::Object {
+class Foo3a<X extends (self::A<Never>) → self::A<dynamic>> extends core::Object {
   synthetic constructor •() → self::Foo3a<self::Foo3a::X>
     ;
 }
@@ -244,11 +244,11 @@
   synthetic constructor •() → self::Foo3b<self::Foo3b::X>
     ;
 }
-class B<X extends core::int = core::int> extends core::Object {
+class B<X extends core::int> extends core::Object {
   synthetic constructor •() → self::B<self::B::X>
     ;
 }
-class Bar3<X extends self::B<core::num> = self::B<core::num>> extends core::Object {
+class Bar3<X extends self::B<core::num>> extends core::Object {
   synthetic constructor •() → self::Bar3<self::Bar3::X>
     ;
 }
@@ -260,7 +260,7 @@
   ;
 static method foo1b((self::A<Never>) → self::A<dynamic> x) → dynamic
   ;
-static method foo2a<X extends (self::A<Never>) → self::A<dynamic> = (self::A<Never>) → self::A<dynamic>>() → dynamic
+static method foo2a<X extends (self::A<Never>) → self::A<dynamic>>() → dynamic
   ;
 static method foo2b<X extends (self::A<Never>) → self::A<dynamic> = dynamic>() → dynamic
   ;
@@ -282,7 +282,7 @@
   ;
 static method bar1(self::B<core::num> x) → dynamic
   ;
-static method bar2<X extends self::B<core::num> = self::B<core::num>>() → dynamic
+static method bar2<X extends self::B<core::num>>() → dynamic
   ;
 static method bar4() → self::B<core::num>
   ;
diff --git a/pkg/front_end/testcases/nnbd/super_bounded_hint.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/super_bounded_hint.dart.weak.transformed.expect
index edb2e83..3a904fc 100644
--- a/pkg/front_end/testcases/nnbd/super_bounded_hint.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/super_bounded_hint.dart.weak.transformed.expect
@@ -533,7 +533,7 @@
     : super core::Object::•()
     ;
 }
-class Foo3a<X extends (self::A<Never>) → self::A<dynamic> = (self::A<Never>) → self::A<dynamic>> extends core::Object {
+class Foo3a<X extends (self::A<Never>) → self::A<dynamic>> extends core::Object {
   synthetic constructor •() → self::Foo3a<self::Foo3a::X>
     : super core::Object::•()
     ;
@@ -543,12 +543,12 @@
     : super core::Object::•()
     ;
 }
-class B<X extends core::int = core::int> extends core::Object {
+class B<X extends core::int> extends core::Object {
   synthetic constructor •() → self::B<self::B::X>
     : super core::Object::•()
     ;
 }
-class Bar3<X extends self::B<core::num> = self::B<core::num>> extends core::Object {
+class Bar3<X extends self::B<core::num>> extends core::Object {
   synthetic constructor •() → self::Bar3<self::Bar3::X>
     : super core::Object::•()
     ;
@@ -560,7 +560,7 @@
 }
 static method foo1a((self::A<Never>) → self::A<dynamic> x) → dynamic {}
 static method foo1b((self::A<Never>) → self::A<dynamic> x) → dynamic {}
-static method foo2a<X extends (self::A<Never>) → self::A<dynamic> = (self::A<Never>) → self::A<dynamic>>() → dynamic {}
+static method foo2a<X extends (self::A<Never>) → self::A<dynamic>>() → dynamic {}
 static method foo2b<X extends (self::A<Never>) → self::A<dynamic> = dynamic>() → dynamic {}
 static method foo4a() → (self::A<Never>) → self::A<dynamic>
   return throw 42;
@@ -578,7 +578,7 @@
     }
   }
   function fooFoo1((self::A<Never>) → self::A<dynamic> x) → Null {}
-  function fooFoo2<X extends (self::A<Never>) → self::A<dynamic> = (self::A<Never>) → self::A<dynamic>>() → Null {}
+  function fooFoo2<X extends (self::A<Never>) → self::A<dynamic>>() → Null {}
   function fooFoo4() → (self::A<Never>) → self::A<dynamic>
     return throw 42;
   function fooFoo5({required (self::A<Never>) → self::A<dynamic> x = #C1}) → Null {}
@@ -594,7 +594,7 @@
     }
   }
   function fooFoo1((self::A<Never>) → self::A<dynamic> x) → Null {}
-  function fooFoo2<X extends (self::A<Never>) → self::A<dynamic> = (self::A<Never>) → self::A<dynamic>>() → Null {}
+  function fooFoo2<X extends (self::A<Never>) → self::A<dynamic>>() → Null {}
   function fooFoo4() → (self::A<Never>) → self::A<dynamic>
     return throw 42;
   function fooFoo5({required (self::A<Never>) → self::A<dynamic> x = #C1}) → Null {}
@@ -603,7 +603,7 @@
 static method foo7a([(self::A<Never>) →? self::A<dynamic> x = #C1]) → dynamic {}
 static method foo7b([(self::A<Never>) →? self::A<dynamic> x = #C1]) → dynamic {}
 static method bar1(self::B<core::num> x) → dynamic {}
-static method bar2<X extends self::B<core::num> = self::B<core::num>>() → dynamic {}
+static method bar2<X extends self::B<core::num>>() → dynamic {}
 static method bar4() → self::B<core::num>
   return throw 42;
 static method bar5({required self::B<core::num> x = #C1}) → dynamic {}
@@ -617,7 +617,7 @@
     }
   }
   function barBar1(self::B<core::num> x) → Null {}
-  function barBar2<X extends self::B<core::num> = self::B<core::num>>() → Null {}
+  function barBar2<X extends self::B<core::num>>() → Null {}
   function barBar4() → self::B<core::num>
     return throw 42;
   function barBar5({required self::B<core::num> x = #C1}) → Null {}
diff --git a/pkg/front_end/testcases/nnbd/tearoff_from_nullable_receiver.dart.strong.expect b/pkg/front_end/testcases/nnbd/tearoff_from_nullable_receiver.dart.strong.expect
index 95d9965..200bf55 100644
--- a/pkg/front_end/testcases/nnbd/tearoff_from_nullable_receiver.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/tearoff_from_nullable_receiver.dart.strong.expect
@@ -54,7 +54,7 @@
 }
 static method functionContext(() → core::int f) → dynamic {}
 static method nullableFunctionContext(() →? core::int f) → dynamic {}
-static method foo<T extends self::C? = self::C?>(self::C? c, self::foo::T% t, self::foo::T? nt) → dynamic {
+static method foo<T extends self::C?>(self::C? c, self::foo::T% t, self::foo::T? nt) → dynamic {
   self::functionContext(let final Never #t1 = invalid-expression "pkg/front_end/testcases/nnbd/tearoff_from_nullable_receiver.dart:14:24: Error: Can't tear off method 'call' from a potentially null value.
   functionContext(null as C?); // Error.
                        ^" in (null as{ForNonNullableByDefault} self::C?) as{TypeError} () → core::int);
@@ -80,7 +80,7 @@
   nullableFunctionContext(nt); // Error.
                           ^" in nt as{TypeError,ForNonNullableByDefault} () →? core::int);
 }
-static method bar<T extends self::C = self::C>(self::C c, self::bar::T t) → dynamic {
+static method bar<T extends self::C>(self::C c, self::bar::T t) → dynamic {
   self::functionContext(let final self::C #t9 = c in #t9.==(null) ?{() → core::int} null : #t9.{self::C::call});
   self::nullableFunctionContext(let final self::C #t10 = c in #t10.==(null) ?{() → core::int} null : #t10.{self::C::call});
   self::functionContext(let final Never #t11 = invalid-expression "pkg/front_end/testcases/nnbd/tearoff_from_nullable_receiver.dart:27:19: Error: The argument type 'T' can't be assigned to the parameter type 'int Function()'.
diff --git a/pkg/front_end/testcases/nnbd/tearoff_from_nullable_receiver.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/tearoff_from_nullable_receiver.dart.strong.transformed.expect
index 116b424..ea7c975 100644
--- a/pkg/front_end/testcases/nnbd/tearoff_from_nullable_receiver.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/tearoff_from_nullable_receiver.dart.strong.transformed.expect
@@ -54,7 +54,7 @@
 }
 static method functionContext(() → core::int f) → dynamic {}
 static method nullableFunctionContext(() →? core::int f) → dynamic {}
-static method foo<T extends self::C? = self::C?>(self::C? c, self::foo::T% t, self::foo::T? nt) → dynamic {
+static method foo<T extends self::C?>(self::C? c, self::foo::T% t, self::foo::T? nt) → dynamic {
   self::functionContext(let final Never #t1 = invalid-expression "pkg/front_end/testcases/nnbd/tearoff_from_nullable_receiver.dart:14:24: Error: Can't tear off method 'call' from a potentially null value.
   functionContext(null as C?); // Error.
                        ^" in let Null #t2 = null in #t2.==(null) ?{() → core::int} #t2 as{TypeError} () → core::int : #t2{() → core::int});
@@ -80,7 +80,7 @@
   nullableFunctionContext(nt); // Error.
                           ^" in nt as{TypeError,ForNonNullableByDefault} () →? core::int);
 }
-static method bar<T extends self::C = self::C>(self::C c, self::bar::T t) → dynamic {
+static method bar<T extends self::C>(self::C c, self::bar::T t) → dynamic {
   self::functionContext(let final self::C #t10 = c in #t10.==(null) ?{() → core::int} null : #t10.{self::C::call});
   self::nullableFunctionContext(let final self::C #t11 = c in #t11.==(null) ?{() → core::int} null : #t11.{self::C::call});
   self::functionContext(let final Never #t12 = invalid-expression "pkg/front_end/testcases/nnbd/tearoff_from_nullable_receiver.dart:27:19: Error: The argument type 'T' can't be assigned to the parameter type 'int Function()'.
diff --git a/pkg/front_end/testcases/nnbd/tearoff_from_nullable_receiver.dart.weak.expect b/pkg/front_end/testcases/nnbd/tearoff_from_nullable_receiver.dart.weak.expect
index 95d9965..200bf55 100644
--- a/pkg/front_end/testcases/nnbd/tearoff_from_nullable_receiver.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/tearoff_from_nullable_receiver.dart.weak.expect
@@ -54,7 +54,7 @@
 }
 static method functionContext(() → core::int f) → dynamic {}
 static method nullableFunctionContext(() →? core::int f) → dynamic {}
-static method foo<T extends self::C? = self::C?>(self::C? c, self::foo::T% t, self::foo::T? nt) → dynamic {
+static method foo<T extends self::C?>(self::C? c, self::foo::T% t, self::foo::T? nt) → dynamic {
   self::functionContext(let final Never #t1 = invalid-expression "pkg/front_end/testcases/nnbd/tearoff_from_nullable_receiver.dart:14:24: Error: Can't tear off method 'call' from a potentially null value.
   functionContext(null as C?); // Error.
                        ^" in (null as{ForNonNullableByDefault} self::C?) as{TypeError} () → core::int);
@@ -80,7 +80,7 @@
   nullableFunctionContext(nt); // Error.
                           ^" in nt as{TypeError,ForNonNullableByDefault} () →? core::int);
 }
-static method bar<T extends self::C = self::C>(self::C c, self::bar::T t) → dynamic {
+static method bar<T extends self::C>(self::C c, self::bar::T t) → dynamic {
   self::functionContext(let final self::C #t9 = c in #t9.==(null) ?{() → core::int} null : #t9.{self::C::call});
   self::nullableFunctionContext(let final self::C #t10 = c in #t10.==(null) ?{() → core::int} null : #t10.{self::C::call});
   self::functionContext(let final Never #t11 = invalid-expression "pkg/front_end/testcases/nnbd/tearoff_from_nullable_receiver.dart:27:19: Error: The argument type 'T' can't be assigned to the parameter type 'int Function()'.
diff --git a/pkg/front_end/testcases/nnbd/tearoff_from_nullable_receiver.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/tearoff_from_nullable_receiver.dart.weak.outline.expect
index bb20d27..cb5a9ee 100644
--- a/pkg/front_end/testcases/nnbd/tearoff_from_nullable_receiver.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/tearoff_from_nullable_receiver.dart.weak.outline.expect
@@ -12,9 +12,9 @@
   ;
 static method nullableFunctionContext(() →? core::int f) → dynamic
   ;
-static method foo<T extends self::C? = self::C?>(self::C? c, self::foo::T% t, self::foo::T? nt) → dynamic
+static method foo<T extends self::C?>(self::C? c, self::foo::T% t, self::foo::T? nt) → dynamic
   ;
-static method bar<T extends self::C = self::C>(self::C c, self::bar::T t) → dynamic
+static method bar<T extends self::C>(self::C c, self::bar::T t) → dynamic
   ;
 static method main() → dynamic
   ;
diff --git a/pkg/front_end/testcases/nnbd/tearoff_from_nullable_receiver.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/tearoff_from_nullable_receiver.dart.weak.transformed.expect
index e84755e..651b955 100644
--- a/pkg/front_end/testcases/nnbd/tearoff_from_nullable_receiver.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/tearoff_from_nullable_receiver.dart.weak.transformed.expect
@@ -54,7 +54,7 @@
 }
 static method functionContext(() → core::int f) → dynamic {}
 static method nullableFunctionContext(() →? core::int f) → dynamic {}
-static method foo<T extends self::C? = self::C?>(self::C? c, self::foo::T% t, self::foo::T? nt) → dynamic {
+static method foo<T extends self::C?>(self::C? c, self::foo::T% t, self::foo::T? nt) → dynamic {
   self::functionContext(let final Never #t1 = invalid-expression "pkg/front_end/testcases/nnbd/tearoff_from_nullable_receiver.dart:14:24: Error: Can't tear off method 'call' from a potentially null value.
   functionContext(null as C?); // Error.
                        ^" in null);
@@ -80,7 +80,7 @@
   nullableFunctionContext(nt); // Error.
                           ^" in nt as{TypeError,ForNonNullableByDefault} () →? core::int);
 }
-static method bar<T extends self::C = self::C>(self::C c, self::bar::T t) → dynamic {
+static method bar<T extends self::C>(self::C c, self::bar::T t) → dynamic {
   self::functionContext(let final self::C #t9 = c in #t9.==(null) ?{() → core::int} null : #t9.{self::C::call});
   self::nullableFunctionContext(let final self::C #t10 = c in #t10.==(null) ?{() → core::int} null : #t10.{self::C::call});
   self::functionContext(let final Never #t11 = invalid-expression "pkg/front_end/testcases/nnbd/tearoff_from_nullable_receiver.dart:27:19: Error: The argument type 'T' can't be assigned to the parameter type 'int Function()'.
diff --git a/pkg/front_end/testcases/nnbd/type_parameter_types.dart.strong.expect b/pkg/front_end/testcases/nnbd/type_parameter_types.dart.strong.expect
index 4db6f6e..9f2387d 100644
--- a/pkg/front_end/testcases/nnbd/type_parameter_types.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/type_parameter_types.dart.strong.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<X extends core::Object = core::Object, Y extends core::Object? = core::Object?> extends core::Object {
+class A<X extends core::Object, Y extends core::Object?> extends core::Object {
   synthetic constructor •() → self::A<self::A::X, self::A::Y%>
     : super core::Object::•()
     ;
@@ -13,7 +13,7 @@
   method baz() → self::A::Y%
     return self::never();
 }
-class B<X extends core::List<self::B::Y%> = core::List<core::Object?>, Y extends core::Object? = core::Object?> extends core::Object {
+class B<X extends core::List<self::B::Y%> = core::List<core::Object?>, Y extends core::Object?> extends core::Object {
   synthetic constructor •() → self::B<self::B::X, self::B::Y%>
     : super core::Object::•()
     ;
@@ -34,13 +34,13 @@
 static method never() → Never
   return throw "Never";
 static method main() → dynamic {
-  function fun1<X extends core::Object = core::Object, Y extends core::Object? = core::Object?>() → X
+  function fun1<X extends core::Object, Y extends core::Object?>() → X
     return self::never();
-  function fun2<X extends core::Object = core::Object, Y extends core::Object? = core::Object?>() → Y%
+  function fun2<X extends core::Object, Y extends core::Object?>() → Y%
     return self::never();
-  function fun3<X extends core::List<Y%> = core::List<core::Object?>, Y extends core::Object? = core::Object?>() → X
+  function fun3<X extends core::List<Y%> = core::List<core::Object?>, Y extends core::Object?>() → X
     return self::never();
-  function fun4<X extends core::List<Y%> = core::List<core::Object?>, Y extends core::Object? = core::Object?>() → Y%
+  function fun4<X extends core::List<Y%> = core::List<core::Object?>, Y extends core::Object?>() → Y%
     return self::never();
   function fun5<X extends core::List<Y%>? = core::List<dynamic>?, Y extends core::List<X%>? = core::List<dynamic>?>() → X%
     return self::never();
diff --git a/pkg/front_end/testcases/nnbd/type_parameter_types.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/type_parameter_types.dart.strong.transformed.expect
index 4db6f6e..9f2387d 100644
--- a/pkg/front_end/testcases/nnbd/type_parameter_types.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/type_parameter_types.dart.strong.transformed.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<X extends core::Object = core::Object, Y extends core::Object? = core::Object?> extends core::Object {
+class A<X extends core::Object, Y extends core::Object?> extends core::Object {
   synthetic constructor •() → self::A<self::A::X, self::A::Y%>
     : super core::Object::•()
     ;
@@ -13,7 +13,7 @@
   method baz() → self::A::Y%
     return self::never();
 }
-class B<X extends core::List<self::B::Y%> = core::List<core::Object?>, Y extends core::Object? = core::Object?> extends core::Object {
+class B<X extends core::List<self::B::Y%> = core::List<core::Object?>, Y extends core::Object?> extends core::Object {
   synthetic constructor •() → self::B<self::B::X, self::B::Y%>
     : super core::Object::•()
     ;
@@ -34,13 +34,13 @@
 static method never() → Never
   return throw "Never";
 static method main() → dynamic {
-  function fun1<X extends core::Object = core::Object, Y extends core::Object? = core::Object?>() → X
+  function fun1<X extends core::Object, Y extends core::Object?>() → X
     return self::never();
-  function fun2<X extends core::Object = core::Object, Y extends core::Object? = core::Object?>() → Y%
+  function fun2<X extends core::Object, Y extends core::Object?>() → Y%
     return self::never();
-  function fun3<X extends core::List<Y%> = core::List<core::Object?>, Y extends core::Object? = core::Object?>() → X
+  function fun3<X extends core::List<Y%> = core::List<core::Object?>, Y extends core::Object?>() → X
     return self::never();
-  function fun4<X extends core::List<Y%> = core::List<core::Object?>, Y extends core::Object? = core::Object?>() → Y%
+  function fun4<X extends core::List<Y%> = core::List<core::Object?>, Y extends core::Object?>() → Y%
     return self::never();
   function fun5<X extends core::List<Y%>? = core::List<dynamic>?, Y extends core::List<X%>? = core::List<dynamic>?>() → X%
     return self::never();
diff --git a/pkg/front_end/testcases/nnbd/type_parameter_types.dart.weak.expect b/pkg/front_end/testcases/nnbd/type_parameter_types.dart.weak.expect
index 8762f10..5992af3 100644
--- a/pkg/front_end/testcases/nnbd/type_parameter_types.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/type_parameter_types.dart.weak.expect
@@ -3,7 +3,7 @@
 import "dart:core" as core;
 import "dart:_internal" as _in;
 
-class A<X extends core::Object = core::Object, Y extends core::Object? = core::Object?> extends core::Object {
+class A<X extends core::Object, Y extends core::Object?> extends core::Object {
   synthetic constructor •() → self::A<self::A::X, self::A::Y%>
     : super core::Object::•()
     ;
@@ -14,7 +14,7 @@
   method baz() → self::A::Y%
     return let final Never #t2 = self::never() in throw new _in::ReachabilityError::•("`null` encountered as the result from expression with type `Never`.");
 }
-class B<X extends core::List<self::B::Y%> = core::List<core::Object?>, Y extends core::Object? = core::Object?> extends core::Object {
+class B<X extends core::List<self::B::Y%> = core::List<core::Object?>, Y extends core::Object?> extends core::Object {
   synthetic constructor •() → self::B<self::B::X, self::B::Y%>
     : super core::Object::•()
     ;
@@ -35,13 +35,13 @@
 static method never() → Never
   return throw "Never";
 static method main() → dynamic {
-  function fun1<X extends core::Object = core::Object, Y extends core::Object? = core::Object?>() → X
+  function fun1<X extends core::Object, Y extends core::Object?>() → X
     return let final Never #t3 = self::never() in throw new _in::ReachabilityError::•("`null` encountered as the result from expression with type `Never`.");
-  function fun2<X extends core::Object = core::Object, Y extends core::Object? = core::Object?>() → Y%
+  function fun2<X extends core::Object, Y extends core::Object?>() → Y%
     return let final Never #t4 = self::never() in throw new _in::ReachabilityError::•("`null` encountered as the result from expression with type `Never`.");
-  function fun3<X extends core::List<Y%> = core::List<core::Object?>, Y extends core::Object? = core::Object?>() → X
+  function fun3<X extends core::List<Y%> = core::List<core::Object?>, Y extends core::Object?>() → X
     return let final Never #t5 = self::never() in throw new _in::ReachabilityError::•("`null` encountered as the result from expression with type `Never`.");
-  function fun4<X extends core::List<Y%> = core::List<core::Object?>, Y extends core::Object? = core::Object?>() → Y%
+  function fun4<X extends core::List<Y%> = core::List<core::Object?>, Y extends core::Object?>() → Y%
     return let final Never #t6 = self::never() in throw new _in::ReachabilityError::•("`null` encountered as the result from expression with type `Never`.");
   function fun5<X extends core::List<Y%>? = core::List<dynamic>?, Y extends core::List<X%>? = core::List<dynamic>?>() → X%
     return let final Never #t7 = self::never() in throw new _in::ReachabilityError::•("`null` encountered as the result from expression with type `Never`.");
diff --git a/pkg/front_end/testcases/nnbd/type_parameter_types.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd/type_parameter_types.dart.weak.outline.expect
index 9c418ba..e50ba48 100644
--- a/pkg/front_end/testcases/nnbd/type_parameter_types.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd/type_parameter_types.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-class A<X extends core::Object = core::Object, Y extends core::Object? = core::Object?> extends core::Object {
+class A<X extends core::Object, Y extends core::Object?> extends core::Object {
   synthetic constructor •() → self::A<self::A::X, self::A::Y%>
     ;
   method foo() → self::A::X
@@ -12,7 +12,7 @@
   method baz() → self::A::Y%
     ;
 }
-class B<X extends core::List<self::B::Y%> = core::List<core::Object?>, Y extends core::Object? = core::Object?> extends core::Object {
+class B<X extends core::List<self::B::Y%> = core::List<core::Object?>, Y extends core::Object?> extends core::Object {
   synthetic constructor •() → self::B<self::B::X, self::B::Y%>
     ;
   method foo(generic-covariant-impl self::B::X x, generic-covariant-impl self::B::Y% y) → dynamic
diff --git a/pkg/front_end/testcases/nnbd/type_parameter_types.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/type_parameter_types.dart.weak.transformed.expect
index 8762f10..5992af3 100644
--- a/pkg/front_end/testcases/nnbd/type_parameter_types.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/type_parameter_types.dart.weak.transformed.expect
@@ -3,7 +3,7 @@
 import "dart:core" as core;
 import "dart:_internal" as _in;
 
-class A<X extends core::Object = core::Object, Y extends core::Object? = core::Object?> extends core::Object {
+class A<X extends core::Object, Y extends core::Object?> extends core::Object {
   synthetic constructor •() → self::A<self::A::X, self::A::Y%>
     : super core::Object::•()
     ;
@@ -14,7 +14,7 @@
   method baz() → self::A::Y%
     return let final Never #t2 = self::never() in throw new _in::ReachabilityError::•("`null` encountered as the result from expression with type `Never`.");
 }
-class B<X extends core::List<self::B::Y%> = core::List<core::Object?>, Y extends core::Object? = core::Object?> extends core::Object {
+class B<X extends core::List<self::B::Y%> = core::List<core::Object?>, Y extends core::Object?> extends core::Object {
   synthetic constructor •() → self::B<self::B::X, self::B::Y%>
     : super core::Object::•()
     ;
@@ -35,13 +35,13 @@
 static method never() → Never
   return throw "Never";
 static method main() → dynamic {
-  function fun1<X extends core::Object = core::Object, Y extends core::Object? = core::Object?>() → X
+  function fun1<X extends core::Object, Y extends core::Object?>() → X
     return let final Never #t3 = self::never() in throw new _in::ReachabilityError::•("`null` encountered as the result from expression with type `Never`.");
-  function fun2<X extends core::Object = core::Object, Y extends core::Object? = core::Object?>() → Y%
+  function fun2<X extends core::Object, Y extends core::Object?>() → Y%
     return let final Never #t4 = self::never() in throw new _in::ReachabilityError::•("`null` encountered as the result from expression with type `Never`.");
-  function fun3<X extends core::List<Y%> = core::List<core::Object?>, Y extends core::Object? = core::Object?>() → X
+  function fun3<X extends core::List<Y%> = core::List<core::Object?>, Y extends core::Object?>() → X
     return let final Never #t5 = self::never() in throw new _in::ReachabilityError::•("`null` encountered as the result from expression with type `Never`.");
-  function fun4<X extends core::List<Y%> = core::List<core::Object?>, Y extends core::Object? = core::Object?>() → Y%
+  function fun4<X extends core::List<Y%> = core::List<core::Object?>, Y extends core::Object?>() → Y%
     return let final Never #t6 = self::never() in throw new _in::ReachabilityError::•("`null` encountered as the result from expression with type `Never`.");
   function fun5<X extends core::List<Y%>? = core::List<dynamic>?, Y extends core::List<X%>? = core::List<dynamic>?>() → X%
     return let final Never #t7 = self::never() in throw new _in::ReachabilityError::•("`null` encountered as the result from expression with type `Never`.");
diff --git a/pkg/front_end/testcases/nnbd_mixed/bounds_from_opt_in.dart.weak.expect b/pkg/front_end/testcases/nnbd_mixed/bounds_from_opt_in.dart.weak.expect
index f315bb6..847ce35 100644
--- a/pkg/front_end/testcases/nnbd_mixed/bounds_from_opt_in.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/bounds_from_opt_in.dart.weak.expect
@@ -5,11 +5,11 @@
 
 import "org-dartlang-testcase:///bounds_from_opt_in_lib.dart";
 
-class LegacyClass<T extends Null = Null> extends bou::Class<self::LegacyClass::T*> {
+class LegacyClass<T extends Null> extends bou::Class<self::LegacyClass::T*> {
   synthetic constructor •() → self::LegacyClass<self::LegacyClass::T*>*
     : super bou::Class::•()
     ;
-  method method<T extends Null = Null>() → dynamic {}
+  method method<T extends Null>() → dynamic {}
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
@@ -32,10 +32,10 @@
 import self as bou;
 import "dart:core" as core;
 
-class Class<T extends Never = Never> extends core::Object {
+class Class<T extends Never> extends core::Object {
   synthetic constructor •() → bou::Class<bou::Class::T>
     : super core::Object::•()
     ;
-  method method<T extends Never = Never>() → dynamic {}
+  method method<T extends Never>() → dynamic {}
 }
-static method method<T extends Never = Never>() → dynamic {}
+static method method<T extends Never>() → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd_mixed/bounds_from_opt_in.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd_mixed/bounds_from_opt_in.dart.weak.outline.expect
index e35c602..ca337ee 100644
--- a/pkg/front_end/testcases/nnbd_mixed/bounds_from_opt_in.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/bounds_from_opt_in.dart.weak.outline.expect
@@ -5,10 +5,10 @@
 
 import "org-dartlang-testcase:///bounds_from_opt_in_lib.dart";
 
-class LegacyClass<T extends Null = Null> extends bou::Class<self::LegacyClass::T*> {
+class LegacyClass<T extends Null> extends bou::Class<self::LegacyClass::T*> {
   synthetic constructor •() → self::LegacyClass<self::LegacyClass::T*>*
     ;
-  method method<T extends Null = Null>() → dynamic
+  method method<T extends Null>() → dynamic
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -30,11 +30,11 @@
 import self as bou;
 import "dart:core" as core;
 
-class Class<T extends Never = Never> extends core::Object {
+class Class<T extends Never> extends core::Object {
   synthetic constructor •() → bou::Class<bou::Class::T>
     ;
-  method method<T extends Never = Never>() → dynamic
+  method method<T extends Never>() → dynamic
     ;
 }
-static method method<T extends Never = Never>() → dynamic
+static method method<T extends Never>() → dynamic
   ;
diff --git a/pkg/front_end/testcases/nnbd_mixed/bounds_from_opt_in.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd_mixed/bounds_from_opt_in.dart.weak.transformed.expect
index f315bb6..847ce35 100644
--- a/pkg/front_end/testcases/nnbd_mixed/bounds_from_opt_in.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/bounds_from_opt_in.dart.weak.transformed.expect
@@ -5,11 +5,11 @@
 
 import "org-dartlang-testcase:///bounds_from_opt_in_lib.dart";
 
-class LegacyClass<T extends Null = Null> extends bou::Class<self::LegacyClass::T*> {
+class LegacyClass<T extends Null> extends bou::Class<self::LegacyClass::T*> {
   synthetic constructor •() → self::LegacyClass<self::LegacyClass::T*>*
     : super bou::Class::•()
     ;
-  method method<T extends Null = Null>() → dynamic {}
+  method method<T extends Null>() → dynamic {}
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
@@ -32,10 +32,10 @@
 import self as bou;
 import "dart:core" as core;
 
-class Class<T extends Never = Never> extends core::Object {
+class Class<T extends Never> extends core::Object {
   synthetic constructor •() → bou::Class<bou::Class::T>
     : super core::Object::•()
     ;
-  method method<T extends Never = Never>() → dynamic {}
+  method method<T extends Never>() → dynamic {}
 }
-static method method<T extends Never = Never>() → dynamic {}
+static method method<T extends Never>() → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd_mixed/const_is.dart.weak.expect b/pkg/front_end/testcases/nnbd_mixed/const_is.dart.weak.expect
index bdcfe75..90ee935 100644
--- a/pkg/front_end/testcases/nnbd_mixed/const_is.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/const_is.dart.weak.expect
@@ -5,7 +5,7 @@
 import "org-dartlang-testcase:///const_is_lib.dart";
 
 static method main() → dynamic {
-  self::expect(true, (#C1) is{ForNonNullableByDefault} <T extends core::Object? = core::Object?>() → void);
+  self::expect(true, (#C1) is{ForNonNullableByDefault} <T extends core::Object?>() → void);
   self::expect(true, #C2);
   self::expect(true, (#C3) is{ForNonNullableByDefault} <T extends Never = dynamic>() → void);
   self::expect(true, #C2);
@@ -19,11 +19,11 @@
 import self as self2;
 import "dart:core" as core;
 
-typedef fnTypeWithNullableObjectBound = <T extends core::Object? = core::Object?>() → void;
+typedef fnTypeWithNullableObjectBound = <T extends core::Object?>() → void;
 typedef fnTypeWithNeverBound = <T extends Never = dynamic>() → void;
-static method fnWithNonNullObjectBound<T extends core::Object = core::Object>() → void
+static method fnWithNonNullObjectBound<T extends core::Object>() → void
   return null;
-static method fnWithNullBound<T extends Null = Null>() → void
+static method fnWithNullBound<T extends Null>() → void
   return null;
 
 constants  {
diff --git a/pkg/front_end/testcases/nnbd_mixed/const_is.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd_mixed/const_is.dart.weak.outline.expect
index a26ee06..928c19a 100644
--- a/pkg/front_end/testcases/nnbd_mixed/const_is.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/const_is.dart.weak.outline.expect
@@ -12,9 +12,9 @@
 import self as self2;
 import "dart:core" as core;
 
-typedef fnTypeWithNullableObjectBound = <T extends core::Object? = core::Object?>() → void;
+typedef fnTypeWithNullableObjectBound = <T extends core::Object?>() → void;
 typedef fnTypeWithNeverBound = <T extends Never = dynamic>() → void;
-static method fnWithNonNullObjectBound<T extends core::Object = core::Object>() → void
+static method fnWithNonNullObjectBound<T extends core::Object>() → void
   ;
-static method fnWithNullBound<T extends Null = Null>() → void
+static method fnWithNullBound<T extends Null>() → void
   ;
diff --git a/pkg/front_end/testcases/nnbd_mixed/const_is.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd_mixed/const_is.dart.weak.transformed.expect
index a2670ba..d198bb9 100644
--- a/pkg/front_end/testcases/nnbd_mixed/const_is.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/const_is.dart.weak.transformed.expect
@@ -5,7 +5,7 @@
 import "org-dartlang-testcase:///const_is_lib.dart";
 
 static method main() → dynamic {
-  self::expect(true, (#C1) is{ForNonNullableByDefault} <T extends core::Object? = core::Object?>() → void);
+  self::expect(true, (#C1) is{ForNonNullableByDefault} <T extends core::Object?>() → void);
   self::expect(true, #C2);
   self::expect(true, (#C3) is{ForNonNullableByDefault} <T extends Never = dynamic>() → void);
   self::expect(true, #C2);
@@ -19,11 +19,11 @@
 import self as self2;
 import "dart:core" as core;
 
-typedef fnTypeWithNullableObjectBound = <T extends core::Object? = core::Object?>() → void;
+typedef fnTypeWithNullableObjectBound = <T extends core::Object?>() → void;
 typedef fnTypeWithNeverBound = <T extends Never = dynamic>() → void;
-static method fnWithNonNullObjectBound<T extends core::Object = core::Object>() → void
+static method fnWithNonNullObjectBound<T extends core::Object>() → void
   return null;
-static method fnWithNullBound<T extends Null = Null>() → void
+static method fnWithNullBound<T extends Null>() → void
   return null;
 
 constants  {
diff --git a/pkg/front_end/testcases/nnbd_mixed/flutter_issue_63029/flutter_issue_63029.dart.weak.expect b/pkg/front_end/testcases/nnbd_mixed/flutter_issue_63029/flutter_issue_63029.dart.weak.expect
index 91bdcec..ab022ec 100644
--- a/pkg/front_end/testcases/nnbd_mixed/flutter_issue_63029/flutter_issue_63029.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/flutter_issue_63029/flutter_issue_63029.dart.weak.expect
@@ -34,7 +34,7 @@
     : super core::Object::•()
     ;
 }
-abstract class B<T extends flu::A = flu::A> extends core::Object {
+abstract class B<T extends flu::A> extends core::Object {
   synthetic constructor •() → flu::B<flu::B::T>
     : super core::Object::•()
     ;
@@ -62,7 +62,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-abstract class D<T extends flu::A* = flu::A*> extends flu::B<flu2::D::T*> implements flu2::C /*isMixinDeclaration*/  {
+abstract class D<T extends flu::A*> extends flu::B<flu2::D::T*> implements flu2::C /*isMixinDeclaration*/  {
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
diff --git a/pkg/front_end/testcases/nnbd_mixed/flutter_issue_63029/flutter_issue_63029.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd_mixed/flutter_issue_63029/flutter_issue_63029.dart.weak.outline.expect
index d6c1469..3bad5bd 100644
--- a/pkg/front_end/testcases/nnbd_mixed/flutter_issue_63029/flutter_issue_63029.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/flutter_issue_63029/flutter_issue_63029.dart.weak.outline.expect
@@ -32,7 +32,7 @@
   synthetic constructor •() → flu::A
     ;
 }
-abstract class B<T extends flu::A = flu::A> extends core::Object {
+abstract class B<T extends flu::A> extends core::Object {
   synthetic constructor •() → flu::B<flu::B::T>
     ;
 }
@@ -58,7 +58,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-abstract class D<T extends flu::A* = flu::A*> extends flu::B<flu2::D::T*> implements flu2::C /*isMixinDeclaration*/  {
+abstract class D<T extends flu::A*> extends flu::B<flu2::D::T*> implements flu2::C /*isMixinDeclaration*/  {
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
diff --git a/pkg/front_end/testcases/nnbd_mixed/flutter_issue_63029/flutter_issue_63029.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd_mixed/flutter_issue_63029/flutter_issue_63029.dart.weak.transformed.expect
index 1009eb9..009be62 100644
--- a/pkg/front_end/testcases/nnbd_mixed/flutter_issue_63029/flutter_issue_63029.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/flutter_issue_63029/flutter_issue_63029.dart.weak.transformed.expect
@@ -34,7 +34,7 @@
     : super core::Object::•()
     ;
 }
-abstract class B<T extends flu::A = flu::A> extends core::Object {
+abstract class B<T extends flu::A> extends core::Object {
   synthetic constructor •() → flu::B<flu::B::T>
     : super core::Object::•()
     ;
@@ -62,7 +62,7 @@
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
-abstract class D<T extends flu::A* = flu::A*> extends flu::B<flu2::D::T*> implements flu2::C /*isMixinDeclaration*/  {
+abstract class D<T extends flu::A*> extends flu::B<flu2::D::T*> implements flu2::C /*isMixinDeclaration*/  {
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
diff --git a/pkg/front_end/testcases/nnbd_mixed/generic_override.dart.weak.expect b/pkg/front_end/testcases/nnbd_mixed/generic_override.dart.weak.expect
index 30674ab..71759ac 100644
--- a/pkg/front_end/testcases/nnbd_mixed/generic_override.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/generic_override.dart.weak.expect
@@ -47,58 +47,58 @@
   abstract method method1a<T extends core::Object? = dynamic>() → void;
   abstract method method1b<T extends core::Object? = dynamic>() → void;
   abstract method method1c<T extends core::Object? = dynamic>() → void;
-  abstract method method2a<T extends core::Object? = core::Object?>() → void;
-  abstract method method2b<T extends core::Object? = core::Object?>() → void;
-  abstract method method2c<T extends core::Object? = core::Object?>() → void;
-  abstract method method3a<T extends dynamic = dynamic>() → void;
-  abstract method method3b<T extends dynamic = dynamic>() → void;
-  abstract method method3c<T extends dynamic = dynamic>() → void;
-  abstract method method4a<T extends core::Object = core::Object>() → void;
-  abstract method method4b<T extends core::Object = core::Object>() → void;
-  abstract method method4c<T extends core::Object? = core::Object?>() → void;
-  abstract method method5a<T extends self::Class1 = self::Class1>() → void;
-  abstract method method5b<T extends self::Class1 = self::Class1>() → void;
-  abstract method method5c<T extends self::Class1? = self::Class1?>() → void;
+  abstract method method2a<T extends core::Object?>() → void;
+  abstract method method2b<T extends core::Object?>() → void;
+  abstract method method2c<T extends core::Object?>() → void;
+  abstract method method3a<T extends dynamic>() → void;
+  abstract method method3b<T extends dynamic>() → void;
+  abstract method method3c<T extends dynamic>() → void;
+  abstract method method4a<T extends core::Object>() → void;
+  abstract method method4b<T extends core::Object>() → void;
+  abstract method method4c<T extends core::Object?>() → void;
+  abstract method method5a<T extends self::Class1>() → void;
+  abstract method method5b<T extends self::Class1>() → void;
+  abstract method method5c<T extends self::Class1?>() → void;
 }
 abstract class Class2 extends self::Class1 {
   synthetic constructor •() → self::Class2
     : super self::Class1::•()
     ;
   abstract method method1a<T extends core::Object? = dynamic>() → void;
-  abstract method method1b<T extends core::Object? = core::Object?>() → void;
-  abstract method method1c<T extends dynamic = dynamic>() → void;
+  abstract method method1b<T extends core::Object?>() → void;
+  abstract method method1c<T extends dynamic>() → void;
   abstract method method2a<T extends core::Object? = dynamic>() → void;
-  abstract method method2b<T extends core::Object? = core::Object?>() → void;
-  abstract method method2c<T extends dynamic = dynamic>() → void;
+  abstract method method2b<T extends core::Object?>() → void;
+  abstract method method2c<T extends dynamic>() → void;
   abstract method method3a<T extends core::Object? = dynamic>() → void;
-  abstract method method3b<T extends core::Object? = core::Object?>() → void;
-  abstract method method3c<T extends dynamic = dynamic>() → void;
-  abstract method method4a<T extends core::Object = core::Object>() → void;
-  abstract method method4b<T extends core::Object? = core::Object?>() → void;
-  abstract method method4c<T extends core::Object = core::Object>() → void;
-  abstract method method5a<T extends self::Class1 = self::Class1>() → void;
-  abstract method method5b<T extends self::Class1? = self::Class1?>() → void;
-  abstract method method5c<T extends self::Class1 = self::Class1>() → void;
+  abstract method method3b<T extends core::Object?>() → void;
+  abstract method method3c<T extends dynamic>() → void;
+  abstract method method4a<T extends core::Object>() → void;
+  abstract method method4b<T extends core::Object?>() → void;
+  abstract method method4c<T extends core::Object>() → void;
+  abstract method method5a<T extends self::Class1>() → void;
+  abstract method method5b<T extends self::Class1?>() → void;
+  abstract method method5c<T extends self::Class1>() → void;
 }
 abstract class Class3 extends gen::LegacyClass1 {
   synthetic constructor •() → self::Class3
     : super gen::LegacyClass1::•()
     ;
   abstract method method1a<T extends core::Object? = dynamic>() → void;
-  abstract method method1b<T extends core::Object? = core::Object?>() → void;
-  abstract method method1c<T extends dynamic = dynamic>() → void;
+  abstract method method1b<T extends core::Object?>() → void;
+  abstract method method1c<T extends dynamic>() → void;
   abstract method method2a<T extends core::Object? = dynamic>() → void;
-  abstract method method2b<T extends core::Object? = core::Object?>() → void;
-  abstract method method2c<T extends dynamic = dynamic>() → void;
+  abstract method method2b<T extends core::Object?>() → void;
+  abstract method method2c<T extends dynamic>() → void;
   abstract method method3a<T extends core::Object? = dynamic>() → void;
-  abstract method method3b<T extends core::Object? = core::Object?>() → void;
-  abstract method method3c<T extends dynamic = dynamic>() → void;
-  abstract method method4a<T extends core::Object = core::Object>() → void;
-  abstract method method4b<T extends core::Object? = core::Object?>() → void;
-  abstract method method4c<T extends core::Object = core::Object>() → void;
-  abstract method method5a<T extends self::Class1 = self::Class1>() → void;
-  abstract method method5b<T extends self::Class1? = self::Class1?>() → void;
-  abstract method method5c<T extends self::Class1 = self::Class1>() → void;
+  abstract method method3b<T extends core::Object?>() → void;
+  abstract method method3c<T extends dynamic>() → void;
+  abstract method method4a<T extends core::Object>() → void;
+  abstract method method4b<T extends core::Object?>() → void;
+  abstract method method4c<T extends core::Object>() → void;
+  abstract method method5a<T extends self::Class1>() → void;
+  abstract method method5b<T extends self::Class1?>() → void;
+  abstract method method5c<T extends self::Class1>() → void;
 }
 static method main() → dynamic {}
 
@@ -116,18 +116,18 @@
   abstract method method1a<T extends core::Object* = dynamic>() → void;
   abstract method method1b<T extends core::Object* = dynamic>() → void;
   abstract method method1c<T extends core::Object* = dynamic>() → void;
-  abstract method method2a<T extends core::Object* = core::Object*>() → void;
-  abstract method method2b<T extends core::Object* = core::Object*>() → void;
-  abstract method method2c<T extends core::Object* = core::Object*>() → void;
-  abstract method method3a<T extends dynamic = dynamic>() → void;
-  abstract method method3b<T extends dynamic = dynamic>() → void;
-  abstract method method3c<T extends dynamic = dynamic>() → void;
-  abstract method method4a<T extends core::Object* = core::Object*>() → void;
-  abstract method method4b<T extends core::Object* = core::Object*>() → void;
-  abstract method method4c<T extends core::Object* = core::Object*>() → void;
-  abstract method method5a<T extends self::Class1* = self::Class1*>() → void;
-  abstract method method5b<T extends self::Class1* = self::Class1*>() → void;
-  abstract method method5c<T extends self::Class1* = self::Class1*>() → void;
+  abstract method method2a<T extends core::Object*>() → void;
+  abstract method method2b<T extends core::Object*>() → void;
+  abstract method method2c<T extends core::Object*>() → void;
+  abstract method method3a<T extends dynamic>() → void;
+  abstract method method3b<T extends dynamic>() → void;
+  abstract method method3c<T extends dynamic>() → void;
+  abstract method method4a<T extends core::Object*>() → void;
+  abstract method method4b<T extends core::Object*>() → void;
+  abstract method method4c<T extends core::Object*>() → void;
+  abstract method method5a<T extends self::Class1*>() → void;
+  abstract method method5b<T extends self::Class1*>() → void;
+  abstract method method5c<T extends self::Class1*>() → void;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
@@ -144,20 +144,20 @@
     : super self::Class1::•()
     ;
   abstract method method1a<T extends core::Object* = dynamic>() → void;
-  abstract method method1b<T extends core::Object* = core::Object*>() → void;
-  abstract method method1c<T extends dynamic = dynamic>() → void;
+  abstract method method1b<T extends core::Object*>() → void;
+  abstract method method1c<T extends dynamic>() → void;
   abstract method method2a<T extends core::Object* = dynamic>() → void;
-  abstract method method2b<T extends core::Object* = core::Object*>() → void;
-  abstract method method2c<T extends dynamic = dynamic>() → void;
+  abstract method method2b<T extends core::Object*>() → void;
+  abstract method method2c<T extends dynamic>() → void;
   abstract method method3a<T extends core::Object* = dynamic>() → void;
-  abstract method method3b<T extends core::Object* = core::Object*>() → void;
-  abstract method method3c<T extends dynamic = dynamic>() → void;
-  abstract method method4a<T extends core::Object* = core::Object*>() → void;
-  abstract method method4b<T extends core::Object* = core::Object*>() → void;
-  abstract method method4c<T extends core::Object* = core::Object*>() → void;
-  abstract method method5a<T extends self::Class1* = self::Class1*>() → void;
-  abstract method method5b<T extends self::Class1* = self::Class1*>() → void;
-  abstract method method5c<T extends self::Class1* = self::Class1*>() → void;
+  abstract method method3b<T extends core::Object*>() → void;
+  abstract method method3c<T extends dynamic>() → void;
+  abstract method method4a<T extends core::Object*>() → void;
+  abstract method method4b<T extends core::Object*>() → void;
+  abstract method method4c<T extends core::Object*>() → void;
+  abstract method method5a<T extends self::Class1*>() → void;
+  abstract method method5b<T extends self::Class1*>() → void;
+  abstract method method5c<T extends self::Class1*>() → void;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
@@ -186,14 +186,14 @@
   abstract member-signature method method1a<T extends core::Object* = dynamic>() → void; -> self::Class1::method1a
   abstract member-signature method method1b<T extends core::Object* = dynamic>() → void; -> self::Class1::method1b
   abstract member-signature method method1c<T extends core::Object* = dynamic>() → void; -> self::Class1::method1c
-  abstract member-signature method method2a<T extends core::Object* = core::Object*>() → void; -> self::Class1::method2a
-  abstract member-signature method method2b<T extends core::Object* = core::Object*>() → void; -> self::Class1::method2b
-  abstract member-signature method method2c<T extends core::Object* = core::Object*>() → void; -> self::Class1::method2c
-  abstract member-signature method method4a<T extends core::Object* = core::Object*>() → void; -> self::Class1::method4a
-  abstract member-signature method method4b<T extends core::Object* = core::Object*>() → void; -> self::Class1::method4b
-  abstract member-signature method method4c<T extends core::Object* = core::Object*>() → void; -> self::Class1::method4c
-  abstract member-signature method method5a<T extends self::Class1* = self::Class1*>() → void; -> self::Class1::method5a
-  abstract member-signature method method5b<T extends self::Class1* = self::Class1*>() → void; -> self::Class1::method5b
-  abstract member-signature method method5c<T extends self::Class1* = self::Class1*>() → void; -> self::Class1::method5c
+  abstract member-signature method method2a<T extends core::Object*>() → void; -> self::Class1::method2a
+  abstract member-signature method method2b<T extends core::Object*>() → void; -> self::Class1::method2b
+  abstract member-signature method method2c<T extends core::Object*>() → void; -> self::Class1::method2c
+  abstract member-signature method method4a<T extends core::Object*>() → void; -> self::Class1::method4a
+  abstract member-signature method method4b<T extends core::Object*>() → void; -> self::Class1::method4b
+  abstract member-signature method method4c<T extends core::Object*>() → void; -> self::Class1::method4c
+  abstract member-signature method method5a<T extends self::Class1*>() → void; -> self::Class1::method5a
+  abstract member-signature method method5b<T extends self::Class1*>() → void; -> self::Class1::method5b
+  abstract member-signature method method5c<T extends self::Class1*>() → void; -> self::Class1::method5c
 }
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd_mixed/generic_override.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd_mixed/generic_override.dart.weak.outline.expect
index ab28d4e..11a11bb 100644
--- a/pkg/front_end/testcases/nnbd_mixed/generic_override.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/generic_override.dart.weak.outline.expect
@@ -46,56 +46,56 @@
   abstract method method1a<T extends core::Object? = dynamic>() → void;
   abstract method method1b<T extends core::Object? = dynamic>() → void;
   abstract method method1c<T extends core::Object? = dynamic>() → void;
-  abstract method method2a<T extends core::Object? = core::Object?>() → void;
-  abstract method method2b<T extends core::Object? = core::Object?>() → void;
-  abstract method method2c<T extends core::Object? = core::Object?>() → void;
-  abstract method method3a<T extends dynamic = dynamic>() → void;
-  abstract method method3b<T extends dynamic = dynamic>() → void;
-  abstract method method3c<T extends dynamic = dynamic>() → void;
-  abstract method method4a<T extends core::Object = core::Object>() → void;
-  abstract method method4b<T extends core::Object = core::Object>() → void;
-  abstract method method4c<T extends core::Object? = core::Object?>() → void;
-  abstract method method5a<T extends self::Class1 = self::Class1>() → void;
-  abstract method method5b<T extends self::Class1 = self::Class1>() → void;
-  abstract method method5c<T extends self::Class1? = self::Class1?>() → void;
+  abstract method method2a<T extends core::Object?>() → void;
+  abstract method method2b<T extends core::Object?>() → void;
+  abstract method method2c<T extends core::Object?>() → void;
+  abstract method method3a<T extends dynamic>() → void;
+  abstract method method3b<T extends dynamic>() → void;
+  abstract method method3c<T extends dynamic>() → void;
+  abstract method method4a<T extends core::Object>() → void;
+  abstract method method4b<T extends core::Object>() → void;
+  abstract method method4c<T extends core::Object?>() → void;
+  abstract method method5a<T extends self::Class1>() → void;
+  abstract method method5b<T extends self::Class1>() → void;
+  abstract method method5c<T extends self::Class1?>() → void;
 }
 abstract class Class2 extends self::Class1 {
   synthetic constructor •() → self::Class2
     ;
   abstract method method1a<T extends core::Object? = dynamic>() → void;
-  abstract method method1b<T extends core::Object? = core::Object?>() → void;
-  abstract method method1c<T extends dynamic = dynamic>() → void;
+  abstract method method1b<T extends core::Object?>() → void;
+  abstract method method1c<T extends dynamic>() → void;
   abstract method method2a<T extends core::Object? = dynamic>() → void;
-  abstract method method2b<T extends core::Object? = core::Object?>() → void;
-  abstract method method2c<T extends dynamic = dynamic>() → void;
+  abstract method method2b<T extends core::Object?>() → void;
+  abstract method method2c<T extends dynamic>() → void;
   abstract method method3a<T extends core::Object? = dynamic>() → void;
-  abstract method method3b<T extends core::Object? = core::Object?>() → void;
-  abstract method method3c<T extends dynamic = dynamic>() → void;
-  abstract method method4a<T extends core::Object = core::Object>() → void;
-  abstract method method4b<T extends core::Object? = core::Object?>() → void;
-  abstract method method4c<T extends core::Object = core::Object>() → void;
-  abstract method method5a<T extends self::Class1 = self::Class1>() → void;
-  abstract method method5b<T extends self::Class1? = self::Class1?>() → void;
-  abstract method method5c<T extends self::Class1 = self::Class1>() → void;
+  abstract method method3b<T extends core::Object?>() → void;
+  abstract method method3c<T extends dynamic>() → void;
+  abstract method method4a<T extends core::Object>() → void;
+  abstract method method4b<T extends core::Object?>() → void;
+  abstract method method4c<T extends core::Object>() → void;
+  abstract method method5a<T extends self::Class1>() → void;
+  abstract method method5b<T extends self::Class1?>() → void;
+  abstract method method5c<T extends self::Class1>() → void;
 }
 abstract class Class3 extends gen::LegacyClass1 {
   synthetic constructor •() → self::Class3
     ;
   abstract method method1a<T extends core::Object? = dynamic>() → void;
-  abstract method method1b<T extends core::Object? = core::Object?>() → void;
-  abstract method method1c<T extends dynamic = dynamic>() → void;
+  abstract method method1b<T extends core::Object?>() → void;
+  abstract method method1c<T extends dynamic>() → void;
   abstract method method2a<T extends core::Object? = dynamic>() → void;
-  abstract method method2b<T extends core::Object? = core::Object?>() → void;
-  abstract method method2c<T extends dynamic = dynamic>() → void;
+  abstract method method2b<T extends core::Object?>() → void;
+  abstract method method2c<T extends dynamic>() → void;
   abstract method method3a<T extends core::Object? = dynamic>() → void;
-  abstract method method3b<T extends core::Object? = core::Object?>() → void;
-  abstract method method3c<T extends dynamic = dynamic>() → void;
-  abstract method method4a<T extends core::Object = core::Object>() → void;
-  abstract method method4b<T extends core::Object? = core::Object?>() → void;
-  abstract method method4c<T extends core::Object = core::Object>() → void;
-  abstract method method5a<T extends self::Class1 = self::Class1>() → void;
-  abstract method method5b<T extends self::Class1? = self::Class1?>() → void;
-  abstract method method5c<T extends self::Class1 = self::Class1>() → void;
+  abstract method method3b<T extends core::Object?>() → void;
+  abstract method method3c<T extends dynamic>() → void;
+  abstract method method4a<T extends core::Object>() → void;
+  abstract method method4b<T extends core::Object?>() → void;
+  abstract method method4c<T extends core::Object>() → void;
+  abstract method method5a<T extends self::Class1>() → void;
+  abstract method method5b<T extends self::Class1?>() → void;
+  abstract method method5c<T extends self::Class1>() → void;
 }
 static method main() → dynamic
   ;
@@ -113,18 +113,18 @@
   abstract method method1a<T extends core::Object* = dynamic>() → void;
   abstract method method1b<T extends core::Object* = dynamic>() → void;
   abstract method method1c<T extends core::Object* = dynamic>() → void;
-  abstract method method2a<T extends core::Object* = core::Object*>() → void;
-  abstract method method2b<T extends core::Object* = core::Object*>() → void;
-  abstract method method2c<T extends core::Object* = core::Object*>() → void;
-  abstract method method3a<T extends dynamic = dynamic>() → void;
-  abstract method method3b<T extends dynamic = dynamic>() → void;
-  abstract method method3c<T extends dynamic = dynamic>() → void;
-  abstract method method4a<T extends core::Object* = core::Object*>() → void;
-  abstract method method4b<T extends core::Object* = core::Object*>() → void;
-  abstract method method4c<T extends core::Object* = core::Object*>() → void;
-  abstract method method5a<T extends self::Class1* = self::Class1*>() → void;
-  abstract method method5b<T extends self::Class1* = self::Class1*>() → void;
-  abstract method method5c<T extends self::Class1* = self::Class1*>() → void;
+  abstract method method2a<T extends core::Object*>() → void;
+  abstract method method2b<T extends core::Object*>() → void;
+  abstract method method2c<T extends core::Object*>() → void;
+  abstract method method3a<T extends dynamic>() → void;
+  abstract method method3b<T extends dynamic>() → void;
+  abstract method method3c<T extends dynamic>() → void;
+  abstract method method4a<T extends core::Object*>() → void;
+  abstract method method4b<T extends core::Object*>() → void;
+  abstract method method4c<T extends core::Object*>() → void;
+  abstract method method5a<T extends self::Class1*>() → void;
+  abstract method method5b<T extends self::Class1*>() → void;
+  abstract method method5c<T extends self::Class1*>() → void;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
@@ -140,20 +140,20 @@
   synthetic constructor •() → gen::LegacyClass2*
     ;
   abstract method method1a<T extends core::Object* = dynamic>() → void;
-  abstract method method1b<T extends core::Object* = core::Object*>() → void;
-  abstract method method1c<T extends dynamic = dynamic>() → void;
+  abstract method method1b<T extends core::Object*>() → void;
+  abstract method method1c<T extends dynamic>() → void;
   abstract method method2a<T extends core::Object* = dynamic>() → void;
-  abstract method method2b<T extends core::Object* = core::Object*>() → void;
-  abstract method method2c<T extends dynamic = dynamic>() → void;
+  abstract method method2b<T extends core::Object*>() → void;
+  abstract method method2c<T extends dynamic>() → void;
   abstract method method3a<T extends core::Object* = dynamic>() → void;
-  abstract method method3b<T extends core::Object* = core::Object*>() → void;
-  abstract method method3c<T extends dynamic = dynamic>() → void;
-  abstract method method4a<T extends core::Object* = core::Object*>() → void;
-  abstract method method4b<T extends core::Object* = core::Object*>() → void;
-  abstract method method4c<T extends core::Object* = core::Object*>() → void;
-  abstract method method5a<T extends self::Class1* = self::Class1*>() → void;
-  abstract method method5b<T extends self::Class1* = self::Class1*>() → void;
-  abstract method method5c<T extends self::Class1* = self::Class1*>() → void;
+  abstract method method3b<T extends core::Object*>() → void;
+  abstract method method3c<T extends dynamic>() → void;
+  abstract method method4a<T extends core::Object*>() → void;
+  abstract method method4b<T extends core::Object*>() → void;
+  abstract method method4c<T extends core::Object*>() → void;
+  abstract method method5a<T extends self::Class1*>() → void;
+  abstract method method5b<T extends self::Class1*>() → void;
+  abstract method method5c<T extends self::Class1*>() → void;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
@@ -181,15 +181,15 @@
   abstract member-signature method method1a<T extends core::Object* = dynamic>() → void; -> self::Class1::method1a
   abstract member-signature method method1b<T extends core::Object* = dynamic>() → void; -> self::Class1::method1b
   abstract member-signature method method1c<T extends core::Object* = dynamic>() → void; -> self::Class1::method1c
-  abstract member-signature method method2a<T extends core::Object* = core::Object*>() → void; -> self::Class1::method2a
-  abstract member-signature method method2b<T extends core::Object* = core::Object*>() → void; -> self::Class1::method2b
-  abstract member-signature method method2c<T extends core::Object* = core::Object*>() → void; -> self::Class1::method2c
-  abstract member-signature method method4a<T extends core::Object* = core::Object*>() → void; -> self::Class1::method4a
-  abstract member-signature method method4b<T extends core::Object* = core::Object*>() → void; -> self::Class1::method4b
-  abstract member-signature method method4c<T extends core::Object* = core::Object*>() → void; -> self::Class1::method4c
-  abstract member-signature method method5a<T extends self::Class1* = self::Class1*>() → void; -> self::Class1::method5a
-  abstract member-signature method method5b<T extends self::Class1* = self::Class1*>() → void; -> self::Class1::method5b
-  abstract member-signature method method5c<T extends self::Class1* = self::Class1*>() → void; -> self::Class1::method5c
+  abstract member-signature method method2a<T extends core::Object*>() → void; -> self::Class1::method2a
+  abstract member-signature method method2b<T extends core::Object*>() → void; -> self::Class1::method2b
+  abstract member-signature method method2c<T extends core::Object*>() → void; -> self::Class1::method2c
+  abstract member-signature method method4a<T extends core::Object*>() → void; -> self::Class1::method4a
+  abstract member-signature method method4b<T extends core::Object*>() → void; -> self::Class1::method4b
+  abstract member-signature method method4c<T extends core::Object*>() → void; -> self::Class1::method4c
+  abstract member-signature method method5a<T extends self::Class1*>() → void; -> self::Class1::method5a
+  abstract member-signature method method5b<T extends self::Class1*>() → void; -> self::Class1::method5b
+  abstract member-signature method method5c<T extends self::Class1*>() → void; -> self::Class1::method5c
 }
 static method main() → dynamic
   ;
diff --git a/pkg/front_end/testcases/nnbd_mixed/generic_override.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd_mixed/generic_override.dart.weak.transformed.expect
index 30674ab..71759ac 100644
--- a/pkg/front_end/testcases/nnbd_mixed/generic_override.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/generic_override.dart.weak.transformed.expect
@@ -47,58 +47,58 @@
   abstract method method1a<T extends core::Object? = dynamic>() → void;
   abstract method method1b<T extends core::Object? = dynamic>() → void;
   abstract method method1c<T extends core::Object? = dynamic>() → void;
-  abstract method method2a<T extends core::Object? = core::Object?>() → void;
-  abstract method method2b<T extends core::Object? = core::Object?>() → void;
-  abstract method method2c<T extends core::Object? = core::Object?>() → void;
-  abstract method method3a<T extends dynamic = dynamic>() → void;
-  abstract method method3b<T extends dynamic = dynamic>() → void;
-  abstract method method3c<T extends dynamic = dynamic>() → void;
-  abstract method method4a<T extends core::Object = core::Object>() → void;
-  abstract method method4b<T extends core::Object = core::Object>() → void;
-  abstract method method4c<T extends core::Object? = core::Object?>() → void;
-  abstract method method5a<T extends self::Class1 = self::Class1>() → void;
-  abstract method method5b<T extends self::Class1 = self::Class1>() → void;
-  abstract method method5c<T extends self::Class1? = self::Class1?>() → void;
+  abstract method method2a<T extends core::Object?>() → void;
+  abstract method method2b<T extends core::Object?>() → void;
+  abstract method method2c<T extends core::Object?>() → void;
+  abstract method method3a<T extends dynamic>() → void;
+  abstract method method3b<T extends dynamic>() → void;
+  abstract method method3c<T extends dynamic>() → void;
+  abstract method method4a<T extends core::Object>() → void;
+  abstract method method4b<T extends core::Object>() → void;
+  abstract method method4c<T extends core::Object?>() → void;
+  abstract method method5a<T extends self::Class1>() → void;
+  abstract method method5b<T extends self::Class1>() → void;
+  abstract method method5c<T extends self::Class1?>() → void;
 }
 abstract class Class2 extends self::Class1 {
   synthetic constructor •() → self::Class2
     : super self::Class1::•()
     ;
   abstract method method1a<T extends core::Object? = dynamic>() → void;
-  abstract method method1b<T extends core::Object? = core::Object?>() → void;
-  abstract method method1c<T extends dynamic = dynamic>() → void;
+  abstract method method1b<T extends core::Object?>() → void;
+  abstract method method1c<T extends dynamic>() → void;
   abstract method method2a<T extends core::Object? = dynamic>() → void;
-  abstract method method2b<T extends core::Object? = core::Object?>() → void;
-  abstract method method2c<T extends dynamic = dynamic>() → void;
+  abstract method method2b<T extends core::Object?>() → void;
+  abstract method method2c<T extends dynamic>() → void;
   abstract method method3a<T extends core::Object? = dynamic>() → void;
-  abstract method method3b<T extends core::Object? = core::Object?>() → void;
-  abstract method method3c<T extends dynamic = dynamic>() → void;
-  abstract method method4a<T extends core::Object = core::Object>() → void;
-  abstract method method4b<T extends core::Object? = core::Object?>() → void;
-  abstract method method4c<T extends core::Object = core::Object>() → void;
-  abstract method method5a<T extends self::Class1 = self::Class1>() → void;
-  abstract method method5b<T extends self::Class1? = self::Class1?>() → void;
-  abstract method method5c<T extends self::Class1 = self::Class1>() → void;
+  abstract method method3b<T extends core::Object?>() → void;
+  abstract method method3c<T extends dynamic>() → void;
+  abstract method method4a<T extends core::Object>() → void;
+  abstract method method4b<T extends core::Object?>() → void;
+  abstract method method4c<T extends core::Object>() → void;
+  abstract method method5a<T extends self::Class1>() → void;
+  abstract method method5b<T extends self::Class1?>() → void;
+  abstract method method5c<T extends self::Class1>() → void;
 }
 abstract class Class3 extends gen::LegacyClass1 {
   synthetic constructor •() → self::Class3
     : super gen::LegacyClass1::•()
     ;
   abstract method method1a<T extends core::Object? = dynamic>() → void;
-  abstract method method1b<T extends core::Object? = core::Object?>() → void;
-  abstract method method1c<T extends dynamic = dynamic>() → void;
+  abstract method method1b<T extends core::Object?>() → void;
+  abstract method method1c<T extends dynamic>() → void;
   abstract method method2a<T extends core::Object? = dynamic>() → void;
-  abstract method method2b<T extends core::Object? = core::Object?>() → void;
-  abstract method method2c<T extends dynamic = dynamic>() → void;
+  abstract method method2b<T extends core::Object?>() → void;
+  abstract method method2c<T extends dynamic>() → void;
   abstract method method3a<T extends core::Object? = dynamic>() → void;
-  abstract method method3b<T extends core::Object? = core::Object?>() → void;
-  abstract method method3c<T extends dynamic = dynamic>() → void;
-  abstract method method4a<T extends core::Object = core::Object>() → void;
-  abstract method method4b<T extends core::Object? = core::Object?>() → void;
-  abstract method method4c<T extends core::Object = core::Object>() → void;
-  abstract method method5a<T extends self::Class1 = self::Class1>() → void;
-  abstract method method5b<T extends self::Class1? = self::Class1?>() → void;
-  abstract method method5c<T extends self::Class1 = self::Class1>() → void;
+  abstract method method3b<T extends core::Object?>() → void;
+  abstract method method3c<T extends dynamic>() → void;
+  abstract method method4a<T extends core::Object>() → void;
+  abstract method method4b<T extends core::Object?>() → void;
+  abstract method method4c<T extends core::Object>() → void;
+  abstract method method5a<T extends self::Class1>() → void;
+  abstract method method5b<T extends self::Class1?>() → void;
+  abstract method method5c<T extends self::Class1>() → void;
 }
 static method main() → dynamic {}
 
@@ -116,18 +116,18 @@
   abstract method method1a<T extends core::Object* = dynamic>() → void;
   abstract method method1b<T extends core::Object* = dynamic>() → void;
   abstract method method1c<T extends core::Object* = dynamic>() → void;
-  abstract method method2a<T extends core::Object* = core::Object*>() → void;
-  abstract method method2b<T extends core::Object* = core::Object*>() → void;
-  abstract method method2c<T extends core::Object* = core::Object*>() → void;
-  abstract method method3a<T extends dynamic = dynamic>() → void;
-  abstract method method3b<T extends dynamic = dynamic>() → void;
-  abstract method method3c<T extends dynamic = dynamic>() → void;
-  abstract method method4a<T extends core::Object* = core::Object*>() → void;
-  abstract method method4b<T extends core::Object* = core::Object*>() → void;
-  abstract method method4c<T extends core::Object* = core::Object*>() → void;
-  abstract method method5a<T extends self::Class1* = self::Class1*>() → void;
-  abstract method method5b<T extends self::Class1* = self::Class1*>() → void;
-  abstract method method5c<T extends self::Class1* = self::Class1*>() → void;
+  abstract method method2a<T extends core::Object*>() → void;
+  abstract method method2b<T extends core::Object*>() → void;
+  abstract method method2c<T extends core::Object*>() → void;
+  abstract method method3a<T extends dynamic>() → void;
+  abstract method method3b<T extends dynamic>() → void;
+  abstract method method3c<T extends dynamic>() → void;
+  abstract method method4a<T extends core::Object*>() → void;
+  abstract method method4b<T extends core::Object*>() → void;
+  abstract method method4c<T extends core::Object*>() → void;
+  abstract method method5a<T extends self::Class1*>() → void;
+  abstract method method5b<T extends self::Class1*>() → void;
+  abstract method method5c<T extends self::Class1*>() → void;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
@@ -144,20 +144,20 @@
     : super self::Class1::•()
     ;
   abstract method method1a<T extends core::Object* = dynamic>() → void;
-  abstract method method1b<T extends core::Object* = core::Object*>() → void;
-  abstract method method1c<T extends dynamic = dynamic>() → void;
+  abstract method method1b<T extends core::Object*>() → void;
+  abstract method method1c<T extends dynamic>() → void;
   abstract method method2a<T extends core::Object* = dynamic>() → void;
-  abstract method method2b<T extends core::Object* = core::Object*>() → void;
-  abstract method method2c<T extends dynamic = dynamic>() → void;
+  abstract method method2b<T extends core::Object*>() → void;
+  abstract method method2c<T extends dynamic>() → void;
   abstract method method3a<T extends core::Object* = dynamic>() → void;
-  abstract method method3b<T extends core::Object* = core::Object*>() → void;
-  abstract method method3c<T extends dynamic = dynamic>() → void;
-  abstract method method4a<T extends core::Object* = core::Object*>() → void;
-  abstract method method4b<T extends core::Object* = core::Object*>() → void;
-  abstract method method4c<T extends core::Object* = core::Object*>() → void;
-  abstract method method5a<T extends self::Class1* = self::Class1*>() → void;
-  abstract method method5b<T extends self::Class1* = self::Class1*>() → void;
-  abstract method method5c<T extends self::Class1* = self::Class1*>() → void;
+  abstract method method3b<T extends core::Object*>() → void;
+  abstract method method3c<T extends dynamic>() → void;
+  abstract method method4a<T extends core::Object*>() → void;
+  abstract method method4b<T extends core::Object*>() → void;
+  abstract method method4c<T extends core::Object*>() → void;
+  abstract method method5a<T extends self::Class1*>() → void;
+  abstract method method5b<T extends self::Class1*>() → void;
+  abstract method method5c<T extends self::Class1*>() → void;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
@@ -186,14 +186,14 @@
   abstract member-signature method method1a<T extends core::Object* = dynamic>() → void; -> self::Class1::method1a
   abstract member-signature method method1b<T extends core::Object* = dynamic>() → void; -> self::Class1::method1b
   abstract member-signature method method1c<T extends core::Object* = dynamic>() → void; -> self::Class1::method1c
-  abstract member-signature method method2a<T extends core::Object* = core::Object*>() → void; -> self::Class1::method2a
-  abstract member-signature method method2b<T extends core::Object* = core::Object*>() → void; -> self::Class1::method2b
-  abstract member-signature method method2c<T extends core::Object* = core::Object*>() → void; -> self::Class1::method2c
-  abstract member-signature method method4a<T extends core::Object* = core::Object*>() → void; -> self::Class1::method4a
-  abstract member-signature method method4b<T extends core::Object* = core::Object*>() → void; -> self::Class1::method4b
-  abstract member-signature method method4c<T extends core::Object* = core::Object*>() → void; -> self::Class1::method4c
-  abstract member-signature method method5a<T extends self::Class1* = self::Class1*>() → void; -> self::Class1::method5a
-  abstract member-signature method method5b<T extends self::Class1* = self::Class1*>() → void; -> self::Class1::method5b
-  abstract member-signature method method5c<T extends self::Class1* = self::Class1*>() → void; -> self::Class1::method5c
+  abstract member-signature method method2a<T extends core::Object*>() → void; -> self::Class1::method2a
+  abstract member-signature method method2b<T extends core::Object*>() → void; -> self::Class1::method2b
+  abstract member-signature method method2c<T extends core::Object*>() → void; -> self::Class1::method2c
+  abstract member-signature method method4a<T extends core::Object*>() → void; -> self::Class1::method4a
+  abstract member-signature method method4b<T extends core::Object*>() → void; -> self::Class1::method4b
+  abstract member-signature method method4c<T extends core::Object*>() → void; -> self::Class1::method4c
+  abstract member-signature method method5a<T extends self::Class1*>() → void; -> self::Class1::method5a
+  abstract member-signature method method5b<T extends self::Class1*>() → void; -> self::Class1::method5b
+  abstract member-signature method method5c<T extends self::Class1*>() → void; -> self::Class1::method5c
 }
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd_mixed/infer_constraints_from_opt_in.dart.weak.expect b/pkg/front_end/testcases/nnbd_mixed/infer_constraints_from_opt_in.dart.weak.expect
index e4cfa36..c66b3a9 100644
--- a/pkg/front_end/testcases/nnbd_mixed/infer_constraints_from_opt_in.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/infer_constraints_from_opt_in.dart.weak.expect
@@ -143,7 +143,7 @@
   synthetic constructor •() → inf::B
     : super core::Object::•()
     ;
-  abstract method bar<X extends core::List<core::int?>? = core::List<core::int?>?>() → inf::B::bar::X%;
+  abstract method bar<X extends core::List<core::int?>?>() → inf::B::bar::X%;
   abstract method foo(core::List<core::int> list) → dynamic;
 }
 static field inf::C<dynamic> field1 = new inf::C::•<dynamic>();
diff --git a/pkg/front_end/testcases/nnbd_mixed/infer_constraints_from_opt_in.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd_mixed/infer_constraints_from_opt_in.dart.weak.outline.expect
index b6062b8..363fbfb 100644
--- a/pkg/front_end/testcases/nnbd_mixed/infer_constraints_from_opt_in.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/infer_constraints_from_opt_in.dart.weak.outline.expect
@@ -47,7 +47,7 @@
 abstract class B extends core::Object {
   synthetic constructor •() → inf::B
     ;
-  abstract method bar<X extends core::List<core::int?>? = core::List<core::int?>?>() → inf::B::bar::X%;
+  abstract method bar<X extends core::List<core::int?>?>() → inf::B::bar::X%;
   abstract method foo(core::List<core::int> list) → dynamic;
 }
 static field inf::C<dynamic> field1;
diff --git a/pkg/front_end/testcases/nnbd_mixed/infer_constraints_from_opt_in.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd_mixed/infer_constraints_from_opt_in.dart.weak.transformed.expect
index d9beb51..97b6ea6 100644
--- a/pkg/front_end/testcases/nnbd_mixed/infer_constraints_from_opt_in.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/infer_constraints_from_opt_in.dart.weak.transformed.expect
@@ -143,7 +143,7 @@
   synthetic constructor •() → inf::B
     : super core::Object::•()
     ;
-  abstract method bar<X extends core::List<core::int?>? = core::List<core::int?>?>() → inf::B::bar::X%;
+  abstract method bar<X extends core::List<core::int?>?>() → inf::B::bar::X%;
   abstract method foo(core::List<core::int> list) → dynamic;
 }
 static field inf::C<dynamic> field1 = new inf::C::•<dynamic>();
diff --git a/pkg/front_end/testcases/nnbd_mixed/infer_in_legacy_from_opted_in.dart.weak.expect b/pkg/front_end/testcases/nnbd_mixed/infer_in_legacy_from_opted_in.dart.weak.expect
index 52dc9a8..2ae2d77 100644
--- a/pkg/front_end/testcases/nnbd_mixed/infer_in_legacy_from_opted_in.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/infer_in_legacy_from_opted_in.dart.weak.expect
@@ -15,6 +15,6 @@
 import "dart:core" as core;
 
 static field core::int y = 42;
-static method foo<T extends core::num = core::num>(inf::foo::T t1, inf::foo::T t2) → inf::foo::T
+static method foo<T extends core::num>(inf::foo::T t1, inf::foo::T t2) → inf::foo::T
   return t1;
 static method baz(core::int? v) → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd_mixed/infer_in_legacy_from_opted_in.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd_mixed/infer_in_legacy_from_opted_in.dart.weak.outline.expect
index f226132..d760b98 100644
--- a/pkg/front_end/testcases/nnbd_mixed/infer_in_legacy_from_opted_in.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/infer_in_legacy_from_opted_in.dart.weak.outline.expect
@@ -14,7 +14,7 @@
 import "dart:core" as core;
 
 static field core::int y;
-static method foo<T extends core::num = core::num>(self2::foo::T t1, self2::foo::T t2) → self2::foo::T
+static method foo<T extends core::num>(self2::foo::T t1, self2::foo::T t2) → self2::foo::T
   ;
 static method baz(core::int? v) → dynamic
   ;
diff --git a/pkg/front_end/testcases/nnbd_mixed/infer_in_legacy_from_opted_in.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd_mixed/infer_in_legacy_from_opted_in.dart.weak.transformed.expect
index 52dc9a8..2ae2d77 100644
--- a/pkg/front_end/testcases/nnbd_mixed/infer_in_legacy_from_opted_in.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/infer_in_legacy_from_opted_in.dart.weak.transformed.expect
@@ -15,6 +15,6 @@
 import "dart:core" as core;
 
 static field core::int y = 42;
-static method foo<T extends core::num = core::num>(inf::foo::T t1, inf::foo::T t2) → inf::foo::T
+static method foo<T extends core::num>(inf::foo::T t1, inf::foo::T t2) → inf::foo::T
   return t1;
 static method baz(core::int? v) → dynamic {}
diff --git a/pkg/front_end/testcases/nnbd_mixed/issue39666.dart.weak.expect b/pkg/front_end/testcases/nnbd_mixed/issue39666.dart.weak.expect
index 42dde26..779a4e3 100644
--- a/pkg/front_end/testcases/nnbd_mixed/issue39666.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/issue39666.dart.weak.expect
@@ -5,7 +5,7 @@
 import "dart:async";
 import "org-dartlang-testcase:///issue39666_lib.dart";
 
-class A<X extends FutureOr<core::List<dynamic>> = FutureOr<core::List<dynamic>>> extends core::Object {
+class A<X extends FutureOr<core::List<dynamic>>> extends core::Object {
   synthetic constructor •() → self::A<self::A::X>
     : super core::Object::•()
     ;
@@ -18,7 +18,7 @@
 
 import "dart:async";
 
-class A<X extends FutureOr<core::List<dynamic>*>* = FutureOr<core::List<dynamic>*>*> extends core::Object {
+class A<X extends FutureOr<core::List<dynamic>*>*> extends core::Object {
   synthetic constructor •() → self2::A<self2::A::X*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nnbd_mixed/issue39666.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd_mixed/issue39666.dart.weak.outline.expect
index e703226..262d2a5 100644
--- a/pkg/front_end/testcases/nnbd_mixed/issue39666.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/issue39666.dart.weak.outline.expect
@@ -5,7 +5,7 @@
 import "dart:async";
 import "org-dartlang-testcase:///issue39666_lib.dart";
 
-class A<X extends FutureOr<core::List<dynamic>> = FutureOr<core::List<dynamic>>> extends core::Object {
+class A<X extends FutureOr<core::List<dynamic>>> extends core::Object {
   synthetic constructor •() → self::A<self::A::X>
     ;
 }
@@ -18,7 +18,7 @@
 
 import "dart:async";
 
-class A<X extends FutureOr<core::List<dynamic>*>* = FutureOr<core::List<dynamic>*>*> extends core::Object {
+class A<X extends FutureOr<core::List<dynamic>*>*> extends core::Object {
   synthetic constructor •() → self2::A<self2::A::X*>*
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
diff --git a/pkg/front_end/testcases/nnbd_mixed/issue39666.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd_mixed/issue39666.dart.weak.transformed.expect
index 42dde26..779a4e3 100644
--- a/pkg/front_end/testcases/nnbd_mixed/issue39666.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/issue39666.dart.weak.transformed.expect
@@ -5,7 +5,7 @@
 import "dart:async";
 import "org-dartlang-testcase:///issue39666_lib.dart";
 
-class A<X extends FutureOr<core::List<dynamic>> = FutureOr<core::List<dynamic>>> extends core::Object {
+class A<X extends FutureOr<core::List<dynamic>>> extends core::Object {
   synthetic constructor •() → self::A<self::A::X>
     : super core::Object::•()
     ;
@@ -18,7 +18,7 @@
 
 import "dart:async";
 
-class A<X extends FutureOr<core::List<dynamic>*>* = FutureOr<core::List<dynamic>*>*> extends core::Object {
+class A<X extends FutureOr<core::List<dynamic>*>*> extends core::Object {
   synthetic constructor •() → self2::A<self2::A::X*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nnbd_mixed/mixin_from_dill2/main.dart.weak.expect b/pkg/front_end/testcases/nnbd_mixed/mixin_from_dill2/main.dart.weak.expect
index 8bc2add..39658bf 100644
--- a/pkg/front_end/testcases/nnbd_mixed/mixin_from_dill2/main.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/mixin_from_dill2/main.dart.weak.expect
@@ -5,7 +5,7 @@
 
 import "org-dartlang-testcase:///main_lib.dart";
 
-abstract class RenderAnimatedOpacityMixin<T extends mai::RenderObject = mai::RenderObject> extends mai::RenderObjectWithChildMixin<self::RenderAnimatedOpacityMixin::T> /*isMixinDeclaration*/  {
+abstract class RenderAnimatedOpacityMixin<T extends mai::RenderObject> extends mai::RenderObjectWithChildMixin<self::RenderAnimatedOpacityMixin::T> /*isMixinDeclaration*/  {
 }
 abstract class _RenderAnimatedOpacity&RenderProxyBox&RenderProxyBoxMixin = mai::RenderProxyBox with mai::RenderProxyBoxMixin<mai::RenderBox> /*isAnonymousMixin*/  {
   synthetic constructor •() → self::_RenderAnimatedOpacity&RenderProxyBox&RenderProxyBoxMixin
@@ -78,17 +78,17 @@
   method hitTestChildren(mai::BoxHitTestResult result, {required mai::Offset position = #C1}) → core::bool
     return false;
 }
-abstract class RenderObjectWithChildMixin<ChildType extends mai::RenderObject = mai::RenderObject> extends mai::RenderObject /*isMixinDeclaration*/  {
+abstract class RenderObjectWithChildMixin<ChildType extends mai::RenderObject> extends mai::RenderObject /*isMixinDeclaration*/  {
   generic-covariant-impl field mai::RenderObjectWithChildMixin::ChildType? _child = null;
   get child() → mai::RenderObjectWithChildMixin::ChildType?
     return this.{mai::RenderObjectWithChildMixin::_child};
 }
-abstract class _RenderProxyBoxMixin&RenderBox&RenderObjectWithChildMixin<T extends mai::RenderBox = mai::RenderBox> extends core::Object implements mai::RenderBox, mai::RenderObjectWithChildMixin<mai::_RenderProxyBoxMixin&RenderBox&RenderObjectWithChildMixin::T> /*isAnonymousMixin*/  {
+abstract class _RenderProxyBoxMixin&RenderBox&RenderObjectWithChildMixin<T extends mai::RenderBox> extends core::Object implements mai::RenderBox, mai::RenderObjectWithChildMixin<mai::_RenderProxyBoxMixin&RenderBox&RenderObjectWithChildMixin::T> /*isAnonymousMixin*/  {
   synthetic constructor •() → mai::_RenderProxyBoxMixin&RenderBox&RenderObjectWithChildMixin<mai::_RenderProxyBoxMixin&RenderBox&RenderObjectWithChildMixin::T>
     : super core::Object::•()
     ;
 }
-abstract class RenderProxyBoxMixin<T extends mai::RenderBox = mai::RenderBox> extends mai::_RenderProxyBoxMixin&RenderBox&RenderObjectWithChildMixin<mai::RenderProxyBoxMixin::T> /*isMixinDeclaration*/  {
+abstract class RenderProxyBoxMixin<T extends mai::RenderBox> extends mai::_RenderProxyBoxMixin&RenderBox&RenderObjectWithChildMixin<mai::RenderProxyBoxMixin::T> /*isMixinDeclaration*/  {
   @#C2
   method hitTestChildren(mai::BoxHitTestResult result, {required mai::Offset position = #C1}) → core::bool {
     return let final core::bool? #t1 = let final mai::RenderProxyBoxMixin::T? #t2 = this.{mai::RenderObjectWithChildMixin::child} in #t2.{core::Object::==}(null) ?{core::bool?} null : #t2{mai::RenderProxyBoxMixin::T}.{mai::RenderBox::hitTest}(result, position: position) in #t1.{core::Object::==}(null) ?{core::bool} false : #t1{core::bool};
diff --git a/pkg/front_end/testcases/nnbd_mixed/mixin_from_dill2/main.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd_mixed/mixin_from_dill2/main.dart.weak.outline.expect
index a221d7d..9cec757 100644
--- a/pkg/front_end/testcases/nnbd_mixed/mixin_from_dill2/main.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/mixin_from_dill2/main.dart.weak.outline.expect
@@ -5,7 +5,7 @@
 
 import "org-dartlang-testcase:///main_lib.dart";
 
-abstract class RenderAnimatedOpacityMixin<T extends mai::RenderObject = mai::RenderObject> extends mai::RenderObjectWithChildMixin<self::RenderAnimatedOpacityMixin::T> /*isMixinDeclaration*/  {
+abstract class RenderAnimatedOpacityMixin<T extends mai::RenderObject> extends mai::RenderObjectWithChildMixin<self::RenderAnimatedOpacityMixin::T> /*isMixinDeclaration*/  {
 }
 abstract class _RenderAnimatedOpacity&RenderProxyBox&RenderProxyBoxMixin = mai::RenderProxyBox with mai::RenderProxyBoxMixin<mai::RenderBox> /*isAnonymousMixin*/  {
   synthetic constructor •() → self::_RenderAnimatedOpacity&RenderProxyBox&RenderProxyBoxMixin
@@ -69,16 +69,16 @@
   method hitTestChildren(mai::BoxHitTestResult result, {required mai::Offset position}) → core::bool
     ;
 }
-abstract class RenderObjectWithChildMixin<ChildType extends mai::RenderObject = mai::RenderObject> extends mai::RenderObject /*isMixinDeclaration*/  {
+abstract class RenderObjectWithChildMixin<ChildType extends mai::RenderObject> extends mai::RenderObject /*isMixinDeclaration*/  {
   generic-covariant-impl field mai::RenderObjectWithChildMixin::ChildType? _child;
   get child() → mai::RenderObjectWithChildMixin::ChildType?
     ;
 }
-abstract class _RenderProxyBoxMixin&RenderBox&RenderObjectWithChildMixin<T extends mai::RenderBox = mai::RenderBox> extends core::Object implements mai::RenderBox, mai::RenderObjectWithChildMixin<mai::_RenderProxyBoxMixin&RenderBox&RenderObjectWithChildMixin::T> /*isAnonymousMixin*/  {
+abstract class _RenderProxyBoxMixin&RenderBox&RenderObjectWithChildMixin<T extends mai::RenderBox> extends core::Object implements mai::RenderBox, mai::RenderObjectWithChildMixin<mai::_RenderProxyBoxMixin&RenderBox&RenderObjectWithChildMixin::T> /*isAnonymousMixin*/  {
   synthetic constructor •() → mai::_RenderProxyBoxMixin&RenderBox&RenderObjectWithChildMixin<mai::_RenderProxyBoxMixin&RenderBox&RenderObjectWithChildMixin::T>
     ;
 }
-abstract class RenderProxyBoxMixin<T extends mai::RenderBox = mai::RenderBox> extends mai::_RenderProxyBoxMixin&RenderBox&RenderObjectWithChildMixin<mai::RenderProxyBoxMixin::T> /*isMixinDeclaration*/  {
+abstract class RenderProxyBoxMixin<T extends mai::RenderBox> extends mai::_RenderProxyBoxMixin&RenderBox&RenderObjectWithChildMixin<mai::RenderProxyBoxMixin::T> /*isMixinDeclaration*/  {
   @#C1
   method hitTestChildren(mai::BoxHitTestResult result, {required mai::Offset position}) → core::bool
     ;
diff --git a/pkg/front_end/testcases/nnbd_mixed/mixin_from_dill2/main.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd_mixed/mixin_from_dill2/main.dart.weak.transformed.expect
index 979cddb..d142fe2 100644
--- a/pkg/front_end/testcases/nnbd_mixed/mixin_from_dill2/main.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/mixin_from_dill2/main.dart.weak.transformed.expect
@@ -5,7 +5,7 @@
 
 import "org-dartlang-testcase:///main_lib.dart";
 
-abstract class RenderAnimatedOpacityMixin<T extends mai::RenderObject = mai::RenderObject> extends mai::RenderObjectWithChildMixin<self::RenderAnimatedOpacityMixin::T> /*isMixinDeclaration*/  {
+abstract class RenderAnimatedOpacityMixin<T extends mai::RenderObject> extends mai::RenderObjectWithChildMixin<self::RenderAnimatedOpacityMixin::T> /*isMixinDeclaration*/  {
 }
 abstract class _RenderAnimatedOpacity&RenderProxyBox&RenderProxyBoxMixin extends mai::RenderProxyBox implements mai::RenderProxyBoxMixin<mai::RenderBox> /*isAnonymousMixin,isEliminatedMixin*/  {
   synthetic constructor •() → self::_RenderAnimatedOpacity&RenderProxyBox&RenderProxyBoxMixin
@@ -80,17 +80,17 @@
   method hitTestChildren(mai::BoxHitTestResult result, {required mai::Offset position = #C2}) → core::bool
     return false;
 }
-abstract class RenderObjectWithChildMixin<ChildType extends mai::RenderObject = mai::RenderObject> extends mai::RenderObject /*isMixinDeclaration*/  {
+abstract class RenderObjectWithChildMixin<ChildType extends mai::RenderObject> extends mai::RenderObject /*isMixinDeclaration*/  {
   generic-covariant-impl field mai::RenderObjectWithChildMixin::ChildType? _child = null;
   get child() → mai::RenderObjectWithChildMixin::ChildType?
     return this.{mai::RenderObjectWithChildMixin::_child};
 }
-abstract class _RenderProxyBoxMixin&RenderBox&RenderObjectWithChildMixin<T extends mai::RenderBox = mai::RenderBox> extends core::Object implements mai::RenderBox, mai::RenderObjectWithChildMixin<mai::_RenderProxyBoxMixin&RenderBox&RenderObjectWithChildMixin::T> /*isAnonymousMixin*/  {
+abstract class _RenderProxyBoxMixin&RenderBox&RenderObjectWithChildMixin<T extends mai::RenderBox> extends core::Object implements mai::RenderBox, mai::RenderObjectWithChildMixin<mai::_RenderProxyBoxMixin&RenderBox&RenderObjectWithChildMixin::T> /*isAnonymousMixin*/  {
   synthetic constructor •() → mai::_RenderProxyBoxMixin&RenderBox&RenderObjectWithChildMixin<mai::_RenderProxyBoxMixin&RenderBox&RenderObjectWithChildMixin::T>
     : super core::Object::•()
     ;
 }
-abstract class RenderProxyBoxMixin<T extends mai::RenderBox = mai::RenderBox> extends mai::_RenderProxyBoxMixin&RenderBox&RenderObjectWithChildMixin<mai::RenderProxyBoxMixin::T> /*isMixinDeclaration*/  {
+abstract class RenderProxyBoxMixin<T extends mai::RenderBox> extends mai::_RenderProxyBoxMixin&RenderBox&RenderObjectWithChildMixin<mai::RenderProxyBoxMixin::T> /*isMixinDeclaration*/  {
   @#C1
   method hitTestChildren(mai::BoxHitTestResult result, {required mai::Offset position = #C2}) → core::bool {
     return let final core::bool? #t3 = let final mai::RenderProxyBoxMixin::T? #t4 = this.{mai::RenderObjectWithChildMixin::child} in #t4.{core::Object::==}(null) ?{core::bool?} null : #t4{mai::RenderProxyBoxMixin::T}.{mai::RenderBox::hitTest}(result, position: position) in #t3.{core::Object::==}(null) ?{core::bool} false : #t3{core::bool};
diff --git a/pkg/front_end/testcases/nnbd_mixed/never_opt_out.dart.weak.expect b/pkg/front_end/testcases/nnbd_mixed/never_opt_out.dart.weak.expect
index 2572b51..2617678 100644
--- a/pkg/front_end/testcases/nnbd_mixed/never_opt_out.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/never_opt_out.dart.weak.expect
@@ -169,7 +169,7 @@
     return null;
   set nullProperty(Null value) → void {}
 }
-class BoundedGenericClass<T extends Never = Never> extends core::Object {
+class BoundedGenericClass<T extends Never> extends core::Object {
   synthetic constructor •() → nev::BoundedGenericClass<nev::BoundedGenericClass::T>
     : super core::Object::•()
     ;
@@ -177,9 +177,9 @@
 late static field Never optInNever;
 static method throwing() → Never
   return throw "Never!";
-static method boundedGenericMethod1<T extends Never = Never>() → nev::boundedGenericMethod1::T
+static method boundedGenericMethod1<T extends Never>() → nev::boundedGenericMethod1::T
   return throw "Should never return";
-static method boundedGenericMethod2<T extends Never = Never>() → core::List<nev::boundedGenericMethod2::T>
+static method boundedGenericMethod2<T extends Never>() → core::List<nev::boundedGenericMethod2::T>
   return <nev::boundedGenericMethod2::T>[];
 
 constants  {
diff --git a/pkg/front_end/testcases/nnbd_mixed/never_opt_out.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd_mixed/never_opt_out.dart.weak.outline.expect
index 32b770e..689fd991 100644
--- a/pkg/front_end/testcases/nnbd_mixed/never_opt_out.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/never_opt_out.dart.weak.outline.expect
@@ -108,14 +108,14 @@
   set nullProperty(Null value) → void
     ;
 }
-class BoundedGenericClass<T extends Never = Never> extends core::Object {
+class BoundedGenericClass<T extends Never> extends core::Object {
   synthetic constructor •() → nev::BoundedGenericClass<nev::BoundedGenericClass::T>
     ;
 }
 late static field Never optInNever;
 static method throwing() → Never
   ;
-static method boundedGenericMethod1<T extends Never = Never>() → nev::boundedGenericMethod1::T
+static method boundedGenericMethod1<T extends Never>() → nev::boundedGenericMethod1::T
   ;
-static method boundedGenericMethod2<T extends Never = Never>() → core::List<nev::boundedGenericMethod2::T>
+static method boundedGenericMethod2<T extends Never>() → core::List<nev::boundedGenericMethod2::T>
   ;
diff --git a/pkg/front_end/testcases/nnbd_mixed/never_opt_out.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd_mixed/never_opt_out.dart.weak.transformed.expect
index ce6f78a..fbb85cb 100644
--- a/pkg/front_end/testcases/nnbd_mixed/never_opt_out.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/never_opt_out.dart.weak.transformed.expect
@@ -169,7 +169,7 @@
     return null;
   set nullProperty(Null value) → void {}
 }
-class BoundedGenericClass<T extends Never = Never> extends core::Object {
+class BoundedGenericClass<T extends Never> extends core::Object {
   synthetic constructor •() → nev::BoundedGenericClass<nev::BoundedGenericClass::T>
     : super core::Object::•()
     ;
@@ -177,9 +177,9 @@
 late static field Never optInNever;
 static method throwing() → Never
   return throw "Never!";
-static method boundedGenericMethod1<T extends Never = Never>() → nev::boundedGenericMethod1::T
+static method boundedGenericMethod1<T extends Never>() → nev::boundedGenericMethod1::T
   return throw "Should never return";
-static method boundedGenericMethod2<T extends Never = Never>() → core::List<nev::boundedGenericMethod2::T>
+static method boundedGenericMethod2<T extends Never>() → core::List<nev::boundedGenericMethod2::T>
   return core::_GrowableList::•<nev::boundedGenericMethod2::T>(0);
 
 constants  {
diff --git a/pkg/front_end/testcases/nnbd_mixed/nsm_from_opt_in.dart.weak.expect b/pkg/front_end/testcases/nnbd_mixed/nsm_from_opt_in.dart.weak.expect
index 561c9cb..16c5070 100644
--- a/pkg/front_end/testcases/nnbd_mixed/nsm_from_opt_in.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/nsm_from_opt_in.dart.weak.expect
@@ -24,8 +24,8 @@
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
   abstract member-signature method method(core::int* i) → core::int*; -> nsm::A::method
   abstract member-signature method genericMethod1<T extends core::Object* = dynamic>(self::A2::genericMethod1::T* t) → self::A2::genericMethod1::T*; -> nsm::A::genericMethod1
-  abstract member-signature method genericMethod2<T extends core::Object* = core::Object*>(self::A2::genericMethod2::T* t) → self::A2::genericMethod2::T*; -> nsm::A::genericMethod2
-  abstract member-signature method genericMethod3<T extends core::Object* = core::Object*>(self::A2::genericMethod3::T* t) → self::A2::genericMethod3::T*; -> nsm::A::genericMethod3
+  abstract member-signature method genericMethod2<T extends core::Object*>(self::A2::genericMethod2::T* t) → self::A2::genericMethod2::T*; -> nsm::A::genericMethod2
+  abstract member-signature method genericMethod3<T extends core::Object*>(self::A2::genericMethod3::T* t) → self::A2::genericMethod3::T*; -> nsm::A::genericMethod3
 }
 abstract class B2 extends nsm::A implements self::C2 {
   synthetic constructor •() → self::B2*
@@ -37,8 +37,8 @@
   }
   abstract member-signature method method(core::int* i, {dynamic optional = #C2}) → core::int*; -> self::C2::method
   abstract member-signature method genericMethod1<T extends core::Object* = dynamic>(self::B2::genericMethod1::T* t) → self::B2::genericMethod1::T*; -> nsm::A::genericMethod1
-  abstract member-signature method genericMethod2<T extends core::Object* = core::Object*>(self::B2::genericMethod2::T* t) → self::B2::genericMethod2::T*; -> nsm::A::genericMethod2
-  abstract member-signature method genericMethod3<T extends core::Object* = core::Object*>(self::B2::genericMethod3::T* t) → self::B2::genericMethod3::T*; -> nsm::A::genericMethod3
+  abstract member-signature method genericMethod2<T extends core::Object*>(self::B2::genericMethod2::T* t) → self::B2::genericMethod2::T*; -> nsm::A::genericMethod2
+  abstract member-signature method genericMethod3<T extends core::Object*>(self::B2::genericMethod3::T* t) → self::B2::genericMethod3::T*; -> nsm::A::genericMethod3
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
@@ -55,8 +55,8 @@
     ;
   abstract method method(core::int* i, {dynamic optional = #C2}) → core::int*;
   abstract method genericMethod1<T extends core::Object* = dynamic>(self::C2::genericMethod1::T* t) → self::C2::genericMethod1::T*;
-  abstract method genericMethod2<T extends core::Object* = core::Object*>(self::C2::genericMethod2::T* t) → self::C2::genericMethod2::T*;
-  abstract method genericMethod3<T extends core::Object* = core::Object*>(self::C2::genericMethod3::T* t) → self::C2::genericMethod3::T*;
+  abstract method genericMethod2<T extends core::Object*>(self::C2::genericMethod2::T* t) → self::C2::genericMethod2::T*;
+  abstract method genericMethod3<T extends core::Object*>(self::C2::genericMethod3::T* t) → self::C2::genericMethod3::T*;
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -82,9 +82,9 @@
     return let final core::int? #t1 = i in #t1.{core::num::==}(null) ?{core::int} 0 : #t1{core::int};
   method genericMethod1<T extends core::Object? = dynamic>(nsm::A::genericMethod1::T% t) → nsm::A::genericMethod1::T%
     return t;
-  method genericMethod2<T extends core::Object? = core::Object?>(nsm::A::genericMethod2::T% t) → nsm::A::genericMethod2::T%
+  method genericMethod2<T extends core::Object?>(nsm::A::genericMethod2::T% t) → nsm::A::genericMethod2::T%
     return t;
-  method genericMethod3<T extends core::Object = core::Object>(nsm::A::genericMethod3::T t) → nsm::A::genericMethod3::T
+  method genericMethod3<T extends core::Object>(nsm::A::genericMethod3::T t) → nsm::A::genericMethod3::T
     return t;
 }
 abstract class B1 extends nsm::A implements nsm::C1 {
@@ -103,8 +103,8 @@
     ;
   abstract method method(core::int? i, {dynamic optional = #C2}) → core::int;
   abstract method genericMethod1<T extends core::Object? = dynamic>(nsm::C1::genericMethod1::T% t) → nsm::C1::genericMethod1::T%;
-  abstract method genericMethod2<T extends core::Object? = core::Object?>(nsm::C1::genericMethod2::T% t) → nsm::C1::genericMethod2::T%;
-  abstract method genericMethod3<T extends core::Object = core::Object>(nsm::C1::genericMethod3::T t) → nsm::C1::genericMethod3::T;
+  abstract method genericMethod2<T extends core::Object?>(nsm::C1::genericMethod2::T% t) → nsm::C1::genericMethod2::T%;
+  abstract method genericMethod3<T extends core::Object>(nsm::C1::genericMethod3::T t) → nsm::C1::genericMethod3::T;
 }
 
 constants  {
diff --git a/pkg/front_end/testcases/nnbd_mixed/nsm_from_opt_in.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd_mixed/nsm_from_opt_in.dart.weak.outline.expect
index b110150..d463ddf 100644
--- a/pkg/front_end/testcases/nnbd_mixed/nsm_from_opt_in.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/nsm_from_opt_in.dart.weak.outline.expect
@@ -22,8 +22,8 @@
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
   abstract member-signature method method(core::int* i) → core::int*; -> nsm::A::method
   abstract member-signature method genericMethod1<T extends core::Object* = dynamic>(self::A2::genericMethod1::T* t) → self::A2::genericMethod1::T*; -> nsm::A::genericMethod1
-  abstract member-signature method genericMethod2<T extends core::Object* = core::Object*>(self::A2::genericMethod2::T* t) → self::A2::genericMethod2::T*; -> nsm::A::genericMethod2
-  abstract member-signature method genericMethod3<T extends core::Object* = core::Object*>(self::A2::genericMethod3::T* t) → self::A2::genericMethod3::T*; -> nsm::A::genericMethod3
+  abstract member-signature method genericMethod2<T extends core::Object*>(self::A2::genericMethod2::T* t) → self::A2::genericMethod2::T*; -> nsm::A::genericMethod2
+  abstract member-signature method genericMethod3<T extends core::Object*>(self::A2::genericMethod3::T* t) → self::A2::genericMethod3::T*; -> nsm::A::genericMethod3
 }
 abstract class B2 extends nsm::A implements self::C2 {
   synthetic constructor •() → self::B2*
@@ -33,8 +33,8 @@
     ;
   abstract member-signature method method(core::int* i, {dynamic optional}) → core::int*; -> self::C2::method
   abstract member-signature method genericMethod1<T extends core::Object* = dynamic>(self::B2::genericMethod1::T* t) → self::B2::genericMethod1::T*; -> nsm::A::genericMethod1
-  abstract member-signature method genericMethod2<T extends core::Object* = core::Object*>(self::B2::genericMethod2::T* t) → self::B2::genericMethod2::T*; -> nsm::A::genericMethod2
-  abstract member-signature method genericMethod3<T extends core::Object* = core::Object*>(self::B2::genericMethod3::T* t) → self::B2::genericMethod3::T*; -> nsm::A::genericMethod3
+  abstract member-signature method genericMethod2<T extends core::Object*>(self::B2::genericMethod2::T* t) → self::B2::genericMethod2::T*; -> nsm::A::genericMethod2
+  abstract member-signature method genericMethod3<T extends core::Object*>(self::B2::genericMethod3::T* t) → self::B2::genericMethod3::T*; -> nsm::A::genericMethod3
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
@@ -50,8 +50,8 @@
     ;
   abstract method method(core::int* i, {dynamic optional}) → core::int*;
   abstract method genericMethod1<T extends core::Object* = dynamic>(self::C2::genericMethod1::T* t) → self::C2::genericMethod1::T*;
-  abstract method genericMethod2<T extends core::Object* = core::Object*>(self::C2::genericMethod2::T* t) → self::C2::genericMethod2::T*;
-  abstract method genericMethod3<T extends core::Object* = core::Object*>(self::C2::genericMethod3::T* t) → self::C2::genericMethod3::T*;
+  abstract method genericMethod2<T extends core::Object*>(self::C2::genericMethod2::T* t) → self::C2::genericMethod2::T*;
+  abstract method genericMethod3<T extends core::Object*>(self::C2::genericMethod3::T* t) → self::C2::genericMethod3::T*;
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -77,9 +77,9 @@
     ;
   method genericMethod1<T extends core::Object? = dynamic>(nsm::A::genericMethod1::T% t) → nsm::A::genericMethod1::T%
     ;
-  method genericMethod2<T extends core::Object? = core::Object?>(nsm::A::genericMethod2::T% t) → nsm::A::genericMethod2::T%
+  method genericMethod2<T extends core::Object?>(nsm::A::genericMethod2::T% t) → nsm::A::genericMethod2::T%
     ;
-  method genericMethod3<T extends core::Object = core::Object>(nsm::A::genericMethod3::T t) → nsm::A::genericMethod3::T
+  method genericMethod3<T extends core::Object>(nsm::A::genericMethod3::T t) → nsm::A::genericMethod3::T
     ;
 }
 abstract class B1 extends nsm::A implements nsm::C1 {
@@ -95,8 +95,8 @@
     ;
   abstract method method(core::int? i, {dynamic optional}) → core::int;
   abstract method genericMethod1<T extends core::Object? = dynamic>(nsm::C1::genericMethod1::T% t) → nsm::C1::genericMethod1::T%;
-  abstract method genericMethod2<T extends core::Object? = core::Object?>(nsm::C1::genericMethod2::T% t) → nsm::C1::genericMethod2::T%;
-  abstract method genericMethod3<T extends core::Object = core::Object>(nsm::C1::genericMethod3::T t) → nsm::C1::genericMethod3::T;
+  abstract method genericMethod2<T extends core::Object?>(nsm::C1::genericMethod2::T% t) → nsm::C1::genericMethod2::T%;
+  abstract method genericMethod3<T extends core::Object>(nsm::C1::genericMethod3::T t) → nsm::C1::genericMethod3::T;
 }
 
 
diff --git a/pkg/front_end/testcases/nnbd_mixed/nsm_from_opt_in.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd_mixed/nsm_from_opt_in.dart.weak.transformed.expect
index 561c9cb..16c5070 100644
--- a/pkg/front_end/testcases/nnbd_mixed/nsm_from_opt_in.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/nsm_from_opt_in.dart.weak.transformed.expect
@@ -24,8 +24,8 @@
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
   abstract member-signature method method(core::int* i) → core::int*; -> nsm::A::method
   abstract member-signature method genericMethod1<T extends core::Object* = dynamic>(self::A2::genericMethod1::T* t) → self::A2::genericMethod1::T*; -> nsm::A::genericMethod1
-  abstract member-signature method genericMethod2<T extends core::Object* = core::Object*>(self::A2::genericMethod2::T* t) → self::A2::genericMethod2::T*; -> nsm::A::genericMethod2
-  abstract member-signature method genericMethod3<T extends core::Object* = core::Object*>(self::A2::genericMethod3::T* t) → self::A2::genericMethod3::T*; -> nsm::A::genericMethod3
+  abstract member-signature method genericMethod2<T extends core::Object*>(self::A2::genericMethod2::T* t) → self::A2::genericMethod2::T*; -> nsm::A::genericMethod2
+  abstract member-signature method genericMethod3<T extends core::Object*>(self::A2::genericMethod3::T* t) → self::A2::genericMethod3::T*; -> nsm::A::genericMethod3
 }
 abstract class B2 extends nsm::A implements self::C2 {
   synthetic constructor •() → self::B2*
@@ -37,8 +37,8 @@
   }
   abstract member-signature method method(core::int* i, {dynamic optional = #C2}) → core::int*; -> self::C2::method
   abstract member-signature method genericMethod1<T extends core::Object* = dynamic>(self::B2::genericMethod1::T* t) → self::B2::genericMethod1::T*; -> nsm::A::genericMethod1
-  abstract member-signature method genericMethod2<T extends core::Object* = core::Object*>(self::B2::genericMethod2::T* t) → self::B2::genericMethod2::T*; -> nsm::A::genericMethod2
-  abstract member-signature method genericMethod3<T extends core::Object* = core::Object*>(self::B2::genericMethod3::T* t) → self::B2::genericMethod3::T*; -> nsm::A::genericMethod3
+  abstract member-signature method genericMethod2<T extends core::Object*>(self::B2::genericMethod2::T* t) → self::B2::genericMethod2::T*; -> nsm::A::genericMethod2
+  abstract member-signature method genericMethod3<T extends core::Object*>(self::B2::genericMethod3::T* t) → self::B2::genericMethod3::T*; -> nsm::A::genericMethod3
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
@@ -55,8 +55,8 @@
     ;
   abstract method method(core::int* i, {dynamic optional = #C2}) → core::int*;
   abstract method genericMethod1<T extends core::Object* = dynamic>(self::C2::genericMethod1::T* t) → self::C2::genericMethod1::T*;
-  abstract method genericMethod2<T extends core::Object* = core::Object*>(self::C2::genericMethod2::T* t) → self::C2::genericMethod2::T*;
-  abstract method genericMethod3<T extends core::Object* = core::Object*>(self::C2::genericMethod3::T* t) → self::C2::genericMethod3::T*;
+  abstract method genericMethod2<T extends core::Object*>(self::C2::genericMethod2::T* t) → self::C2::genericMethod2::T*;
+  abstract method genericMethod3<T extends core::Object*>(self::C2::genericMethod3::T* t) → self::C2::genericMethod3::T*;
   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
@@ -82,9 +82,9 @@
     return let final core::int? #t1 = i in #t1.{core::num::==}(null) ?{core::int} 0 : #t1{core::int};
   method genericMethod1<T extends core::Object? = dynamic>(nsm::A::genericMethod1::T% t) → nsm::A::genericMethod1::T%
     return t;
-  method genericMethod2<T extends core::Object? = core::Object?>(nsm::A::genericMethod2::T% t) → nsm::A::genericMethod2::T%
+  method genericMethod2<T extends core::Object?>(nsm::A::genericMethod2::T% t) → nsm::A::genericMethod2::T%
     return t;
-  method genericMethod3<T extends core::Object = core::Object>(nsm::A::genericMethod3::T t) → nsm::A::genericMethod3::T
+  method genericMethod3<T extends core::Object>(nsm::A::genericMethod3::T t) → nsm::A::genericMethod3::T
     return t;
 }
 abstract class B1 extends nsm::A implements nsm::C1 {
@@ -103,8 +103,8 @@
     ;
   abstract method method(core::int? i, {dynamic optional = #C2}) → core::int;
   abstract method genericMethod1<T extends core::Object? = dynamic>(nsm::C1::genericMethod1::T% t) → nsm::C1::genericMethod1::T%;
-  abstract method genericMethod2<T extends core::Object? = core::Object?>(nsm::C1::genericMethod2::T% t) → nsm::C1::genericMethod2::T%;
-  abstract method genericMethod3<T extends core::Object = core::Object>(nsm::C1::genericMethod3::T t) → nsm::C1::genericMethod3::T;
+  abstract method genericMethod2<T extends core::Object?>(nsm::C1::genericMethod2::T% t) → nsm::C1::genericMethod2::T%;
+  abstract method genericMethod3<T extends core::Object>(nsm::C1::genericMethod3::T t) → nsm::C1::genericMethod3::T;
 }
 
 constants  {
diff --git a/pkg/front_end/testcases/nnbd_mixed/object_bound_factory/main.dart.weak.expect b/pkg/front_end/testcases/nnbd_mixed/object_bound_factory/main.dart.weak.expect
index 964ecb3..c8d8780 100644
--- a/pkg/front_end/testcases/nnbd_mixed/object_bound_factory/main.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/object_bound_factory/main.dart.weak.expect
@@ -33,40 +33,40 @@
 import self as opt;
 import "dart:core" as core;
 
-class Class1<T extends core::Object? = core::Object?> extends core::Object /*hasConstConstructor*/  {
+class Class1<T extends core::Object?> extends core::Object /*hasConstConstructor*/  {
   static final field dynamic _redirecting# = <dynamic>[opt::Class1::redirect, opt::Class1::constRedirect]/*isLegacy*/;
   const constructor _() → opt::Class1<opt::Class1::T%>
     : super core::Object::•()
     ;
-  static factory redirect<T extends core::Object? = core::Object?>() → opt::Class1<opt::Class1::redirect::T%>
+  static factory redirect<T extends core::Object?>() → opt::Class1<opt::Class1::redirect::T%>
     let dynamic #redirecting_factory = opt::Class1::_ in let opt::Class1::redirect::T% #typeArg0 = null in invalid-expression;
-  static factory constRedirect<T extends core::Object? = core::Object?>() → opt::Class1<opt::Class1::constRedirect::T%>
+  static factory constRedirect<T extends core::Object?>() → opt::Class1<opt::Class1::constRedirect::T%>
     let dynamic #redirecting_factory = opt::Class1::_ in let opt::Class1::constRedirect::T% #typeArg0 = null in invalid-expression;
-  static factory fact<T extends core::Object? = core::Object?>() → opt::Class1<opt::Class1::fact::T%>
+  static factory fact<T extends core::Object?>() → opt::Class1<opt::Class1::fact::T%>
     return new opt::Class1::_<opt::Class1::fact::T%>();
 }
-class Class2<T extends core::Object = core::Object> extends core::Object /*hasConstConstructor*/  {
+class Class2<T extends core::Object> extends core::Object /*hasConstConstructor*/  {
   static final field dynamic _redirecting# = <dynamic>[opt::Class2::redirect, opt::Class2::constRedirect]/*isLegacy*/;
   const constructor _() → opt::Class2<opt::Class2::T>
     : super core::Object::•()
     ;
-  static factory redirect<T extends core::Object = core::Object>() → opt::Class2<opt::Class2::redirect::T>
+  static factory redirect<T extends core::Object>() → opt::Class2<opt::Class2::redirect::T>
     let dynamic #redirecting_factory = opt::Class2::_ in let opt::Class2::redirect::T #typeArg0 = null in invalid-expression;
-  static factory constRedirect<T extends core::Object = core::Object>() → opt::Class2<opt::Class2::constRedirect::T>
+  static factory constRedirect<T extends core::Object>() → opt::Class2<opt::Class2::constRedirect::T>
     let dynamic #redirecting_factory = opt::Class2::_ in let opt::Class2::constRedirect::T #typeArg0 = null in invalid-expression;
-  static factory fact<T extends core::Object = core::Object>() → opt::Class2<opt::Class2::fact::T>
+  static factory fact<T extends core::Object>() → opt::Class2<opt::Class2::fact::T>
     return new opt::Class2::_<opt::Class2::fact::T>();
 }
-class Class3<T extends core::String = core::String> extends core::Object /*hasConstConstructor*/  {
+class Class3<T extends core::String> extends core::Object /*hasConstConstructor*/  {
   static final field dynamic _redirecting# = <dynamic>[opt::Class3::redirect, opt::Class3::constRedirect]/*isLegacy*/;
   const constructor _() → opt::Class3<opt::Class3::T>
     : super core::Object::•()
     ;
-  static factory redirect<T extends core::String = core::String>() → opt::Class3<opt::Class3::redirect::T>
+  static factory redirect<T extends core::String>() → opt::Class3<opt::Class3::redirect::T>
     let dynamic #redirecting_factory = opt::Class3::_ in let opt::Class3::redirect::T #typeArg0 = null in invalid-expression;
-  static factory constRedirect<T extends core::String = core::String>() → opt::Class3<opt::Class3::constRedirect::T>
+  static factory constRedirect<T extends core::String>() → opt::Class3<opt::Class3::constRedirect::T>
     let dynamic #redirecting_factory = opt::Class3::_ in let opt::Class3::constRedirect::T #typeArg0 = null in invalid-expression;
-  static factory fact<T extends core::String = core::String>() → opt::Class3<opt::Class3::fact::T>
+  static factory fact<T extends core::String>() → opt::Class3<opt::Class3::fact::T>
     return new opt::Class3::_<opt::Class3::fact::T>();
 }
 class Class4<T extends core::Object? = dynamic> extends core::Object /*hasConstConstructor*/  {
@@ -81,16 +81,16 @@
   static factory fact<T extends core::Object? = dynamic>() → opt::Class4<opt::Class4::fact::T%>
     return new opt::Class4::_<opt::Class4::fact::T%>();
 }
-class Class5<T extends dynamic = dynamic> extends core::Object /*hasConstConstructor*/  {
+class Class5<T extends dynamic> extends core::Object /*hasConstConstructor*/  {
   static final field dynamic _redirecting# = <dynamic>[opt::Class5::redirect, opt::Class5::constRedirect]/*isLegacy*/;
   const constructor _() → opt::Class5<opt::Class5::T%>
     : super core::Object::•()
     ;
-  static factory redirect<T extends dynamic = dynamic>() → opt::Class5<opt::Class5::redirect::T%>
+  static factory redirect<T extends dynamic>() → opt::Class5<opt::Class5::redirect::T%>
     let dynamic #redirecting_factory = opt::Class5::_ in let opt::Class5::redirect::T% #typeArg0 = null in invalid-expression;
-  static factory constRedirect<T extends dynamic = dynamic>() → opt::Class5<opt::Class5::constRedirect::T%>
+  static factory constRedirect<T extends dynamic>() → opt::Class5<opt::Class5::constRedirect::T%>
     let dynamic #redirecting_factory = opt::Class5::_ in let opt::Class5::constRedirect::T% #typeArg0 = null in invalid-expression;
-  static factory fact<T extends dynamic = dynamic>() → opt::Class5<opt::Class5::fact::T%>
+  static factory fact<T extends dynamic>() → opt::Class5<opt::Class5::fact::T%>
     return new opt::Class5::_<opt::Class5::fact::T%>();
 }
 static method testOptIn() → dynamic {
diff --git a/pkg/front_end/testcases/nnbd_mixed/object_bound_factory/main.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd_mixed/object_bound_factory/main.dart.weak.outline.expect
index 64dc146..f70672f 100644
--- a/pkg/front_end/testcases/nnbd_mixed/object_bound_factory/main.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/object_bound_factory/main.dart.weak.outline.expect
@@ -10,40 +10,40 @@
 import self as self2;
 import "dart:core" as core;
 
-class Class1<T extends core::Object? = core::Object?> extends core::Object /*hasConstConstructor*/  {
+class Class1<T extends core::Object?> extends core::Object /*hasConstConstructor*/  {
   static final field dynamic _redirecting# = <dynamic>[self2::Class1::redirect, self2::Class1::constRedirect]/*isLegacy*/;
   const constructor _() → self2::Class1<self2::Class1::T%>
     : super core::Object::•()
     ;
-  static factory redirect<T extends core::Object? = core::Object?>() → self2::Class1<self2::Class1::redirect::T%>
+  static factory redirect<T extends core::Object?>() → self2::Class1<self2::Class1::redirect::T%>
     let dynamic #redirecting_factory = self2::Class1::_ in let self2::Class1::redirect::T% #typeArg0 = null in invalid-expression;
-  static factory constRedirect<T extends core::Object? = core::Object?>() → self2::Class1<self2::Class1::constRedirect::T%>
+  static factory constRedirect<T extends core::Object?>() → self2::Class1<self2::Class1::constRedirect::T%>
     let dynamic #redirecting_factory = self2::Class1::_ in let self2::Class1::constRedirect::T% #typeArg0 = null in invalid-expression;
-  static factory fact<T extends core::Object? = core::Object?>() → self2::Class1<self2::Class1::fact::T%>
+  static factory fact<T extends core::Object?>() → self2::Class1<self2::Class1::fact::T%>
     ;
 }
-class Class2<T extends core::Object = core::Object> extends core::Object /*hasConstConstructor*/  {
+class Class2<T extends core::Object> extends core::Object /*hasConstConstructor*/  {
   static final field dynamic _redirecting# = <dynamic>[self2::Class2::redirect, self2::Class2::constRedirect]/*isLegacy*/;
   const constructor _() → self2::Class2<self2::Class2::T>
     : super core::Object::•()
     ;
-  static factory redirect<T extends core::Object = core::Object>() → self2::Class2<self2::Class2::redirect::T>
+  static factory redirect<T extends core::Object>() → self2::Class2<self2::Class2::redirect::T>
     let dynamic #redirecting_factory = self2::Class2::_ in let self2::Class2::redirect::T #typeArg0 = null in invalid-expression;
-  static factory constRedirect<T extends core::Object = core::Object>() → self2::Class2<self2::Class2::constRedirect::T>
+  static factory constRedirect<T extends core::Object>() → self2::Class2<self2::Class2::constRedirect::T>
     let dynamic #redirecting_factory = self2::Class2::_ in let self2::Class2::constRedirect::T #typeArg0 = null in invalid-expression;
-  static factory fact<T extends core::Object = core::Object>() → self2::Class2<self2::Class2::fact::T>
+  static factory fact<T extends core::Object>() → self2::Class2<self2::Class2::fact::T>
     ;
 }
-class Class3<T extends core::String = core::String> extends core::Object /*hasConstConstructor*/  {
+class Class3<T extends core::String> extends core::Object /*hasConstConstructor*/  {
   static final field dynamic _redirecting# = <dynamic>[self2::Class3::redirect, self2::Class3::constRedirect]/*isLegacy*/;
   const constructor _() → self2::Class3<self2::Class3::T>
     : super core::Object::•()
     ;
-  static factory redirect<T extends core::String = core::String>() → self2::Class3<self2::Class3::redirect::T>
+  static factory redirect<T extends core::String>() → self2::Class3<self2::Class3::redirect::T>
     let dynamic #redirecting_factory = self2::Class3::_ in let self2::Class3::redirect::T #typeArg0 = null in invalid-expression;
-  static factory constRedirect<T extends core::String = core::String>() → self2::Class3<self2::Class3::constRedirect::T>
+  static factory constRedirect<T extends core::String>() → self2::Class3<self2::Class3::constRedirect::T>
     let dynamic #redirecting_factory = self2::Class3::_ in let self2::Class3::constRedirect::T #typeArg0 = null in invalid-expression;
-  static factory fact<T extends core::String = core::String>() → self2::Class3<self2::Class3::fact::T>
+  static factory fact<T extends core::String>() → self2::Class3<self2::Class3::fact::T>
     ;
 }
 class Class4<T extends core::Object? = dynamic> extends core::Object /*hasConstConstructor*/  {
@@ -58,16 +58,16 @@
   static factory fact<T extends core::Object? = dynamic>() → self2::Class4<self2::Class4::fact::T%>
     ;
 }
-class Class5<T extends dynamic = dynamic> extends core::Object /*hasConstConstructor*/  {
+class Class5<T extends dynamic> extends core::Object /*hasConstConstructor*/  {
   static final field dynamic _redirecting# = <dynamic>[self2::Class5::redirect, self2::Class5::constRedirect]/*isLegacy*/;
   const constructor _() → self2::Class5<self2::Class5::T%>
     : super core::Object::•()
     ;
-  static factory redirect<T extends dynamic = dynamic>() → self2::Class5<self2::Class5::redirect::T%>
+  static factory redirect<T extends dynamic>() → self2::Class5<self2::Class5::redirect::T%>
     let dynamic #redirecting_factory = self2::Class5::_ in let self2::Class5::redirect::T% #typeArg0 = null in invalid-expression;
-  static factory constRedirect<T extends dynamic = dynamic>() → self2::Class5<self2::Class5::constRedirect::T%>
+  static factory constRedirect<T extends dynamic>() → self2::Class5<self2::Class5::constRedirect::T%>
     let dynamic #redirecting_factory = self2::Class5::_ in let self2::Class5::constRedirect::T% #typeArg0 = null in invalid-expression;
-  static factory fact<T extends dynamic = dynamic>() → self2::Class5<self2::Class5::fact::T%>
+  static factory fact<T extends dynamic>() → self2::Class5<self2::Class5::fact::T%>
     ;
 }
 static method testOptIn() → dynamic
diff --git a/pkg/front_end/testcases/nnbd_mixed/object_bound_factory/main.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd_mixed/object_bound_factory/main.dart.weak.transformed.expect
index 460ddca..93eb282 100644
--- a/pkg/front_end/testcases/nnbd_mixed/object_bound_factory/main.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/object_bound_factory/main.dart.weak.transformed.expect
@@ -33,40 +33,40 @@
 import self as opt;
 import "dart:core" as core;
 
-class Class1<T extends core::Object? = core::Object?> extends core::Object /*hasConstConstructor*/  {
+class Class1<T extends core::Object?> extends core::Object /*hasConstConstructor*/  {
   static final field dynamic _redirecting# = <dynamic>[opt::Class1::redirect, opt::Class1::constRedirect]/*isLegacy*/;
   const constructor _() → opt::Class1<opt::Class1::T%>
     : super core::Object::•()
     ;
-  static factory redirect<T extends core::Object? = core::Object?>() → opt::Class1<opt::Class1::redirect::T%>
+  static factory redirect<T extends core::Object?>() → opt::Class1<opt::Class1::redirect::T%>
     let Never #redirecting_factory = opt::Class1::_ in let opt::Class1::redirect::T% #typeArg0 = null in invalid-expression;
-  static factory constRedirect<T extends core::Object? = core::Object?>() → opt::Class1<opt::Class1::constRedirect::T%>
+  static factory constRedirect<T extends core::Object?>() → opt::Class1<opt::Class1::constRedirect::T%>
     let Never #redirecting_factory = opt::Class1::_ in let opt::Class1::constRedirect::T% #typeArg0 = null in invalid-expression;
-  static factory fact<T extends core::Object? = core::Object?>() → opt::Class1<opt::Class1::fact::T%>
+  static factory fact<T extends core::Object?>() → opt::Class1<opt::Class1::fact::T%>
     return new opt::Class1::_<opt::Class1::fact::T%>();
 }
-class Class2<T extends core::Object = core::Object> extends core::Object /*hasConstConstructor*/  {
+class Class2<T extends core::Object> extends core::Object /*hasConstConstructor*/  {
   static final field dynamic _redirecting# = <dynamic>[opt::Class2::redirect, opt::Class2::constRedirect]/*isLegacy*/;
   const constructor _() → opt::Class2<opt::Class2::T>
     : super core::Object::•()
     ;
-  static factory redirect<T extends core::Object = core::Object>() → opt::Class2<opt::Class2::redirect::T>
+  static factory redirect<T extends core::Object>() → opt::Class2<opt::Class2::redirect::T>
     let Never #redirecting_factory = opt::Class2::_ in let opt::Class2::redirect::T #typeArg0 = null in invalid-expression;
-  static factory constRedirect<T extends core::Object = core::Object>() → opt::Class2<opt::Class2::constRedirect::T>
+  static factory constRedirect<T extends core::Object>() → opt::Class2<opt::Class2::constRedirect::T>
     let Never #redirecting_factory = opt::Class2::_ in let opt::Class2::constRedirect::T #typeArg0 = null in invalid-expression;
-  static factory fact<T extends core::Object = core::Object>() → opt::Class2<opt::Class2::fact::T>
+  static factory fact<T extends core::Object>() → opt::Class2<opt::Class2::fact::T>
     return new opt::Class2::_<opt::Class2::fact::T>();
 }
-class Class3<T extends core::String = core::String> extends core::Object /*hasConstConstructor*/  {
+class Class3<T extends core::String> extends core::Object /*hasConstConstructor*/  {
   static final field dynamic _redirecting# = <dynamic>[opt::Class3::redirect, opt::Class3::constRedirect]/*isLegacy*/;
   const constructor _() → opt::Class3<opt::Class3::T>
     : super core::Object::•()
     ;
-  static factory redirect<T extends core::String = core::String>() → opt::Class3<opt::Class3::redirect::T>
+  static factory redirect<T extends core::String>() → opt::Class3<opt::Class3::redirect::T>
     let Never #redirecting_factory = opt::Class3::_ in let opt::Class3::redirect::T #typeArg0 = null in invalid-expression;
-  static factory constRedirect<T extends core::String = core::String>() → opt::Class3<opt::Class3::constRedirect::T>
+  static factory constRedirect<T extends core::String>() → opt::Class3<opt::Class3::constRedirect::T>
     let Never #redirecting_factory = opt::Class3::_ in let opt::Class3::constRedirect::T #typeArg0 = null in invalid-expression;
-  static factory fact<T extends core::String = core::String>() → opt::Class3<opt::Class3::fact::T>
+  static factory fact<T extends core::String>() → opt::Class3<opt::Class3::fact::T>
     return new opt::Class3::_<opt::Class3::fact::T>();
 }
 class Class4<T extends core::Object? = dynamic> extends core::Object /*hasConstConstructor*/  {
@@ -81,16 +81,16 @@
   static factory fact<T extends core::Object? = dynamic>() → opt::Class4<opt::Class4::fact::T%>
     return new opt::Class4::_<opt::Class4::fact::T%>();
 }
-class Class5<T extends dynamic = dynamic> extends core::Object /*hasConstConstructor*/  {
+class Class5<T extends dynamic> extends core::Object /*hasConstConstructor*/  {
   static final field dynamic _redirecting# = <dynamic>[opt::Class5::redirect, opt::Class5::constRedirect]/*isLegacy*/;
   const constructor _() → opt::Class5<opt::Class5::T%>
     : super core::Object::•()
     ;
-  static factory redirect<T extends dynamic = dynamic>() → opt::Class5<opt::Class5::redirect::T%>
+  static factory redirect<T extends dynamic>() → opt::Class5<opt::Class5::redirect::T%>
     let Never #redirecting_factory = opt::Class5::_ in let opt::Class5::redirect::T% #typeArg0 = null in invalid-expression;
-  static factory constRedirect<T extends dynamic = dynamic>() → opt::Class5<opt::Class5::constRedirect::T%>
+  static factory constRedirect<T extends dynamic>() → opt::Class5<opt::Class5::constRedirect::T%>
     let Never #redirecting_factory = opt::Class5::_ in let opt::Class5::constRedirect::T% #typeArg0 = null in invalid-expression;
-  static factory fact<T extends dynamic = dynamic>() → opt::Class5<opt::Class5::fact::T%>
+  static factory fact<T extends dynamic>() → opt::Class5<opt::Class5::fact::T%>
     return new opt::Class5::_<opt::Class5::fact::T%>();
 }
 static method testOptIn() → dynamic {
diff --git a/pkg/front_end/testcases/nnbd_mixed/object_bound_redirecting_factory/main.dart.weak.expect b/pkg/front_end/testcases/nnbd_mixed/object_bound_redirecting_factory/main.dart.weak.expect
index f9e81d9..7ffad38 100644
--- a/pkg/front_end/testcases/nnbd_mixed/object_bound_redirecting_factory/main.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/object_bound_redirecting_factory/main.dart.weak.expect
@@ -43,31 +43,31 @@
 import self as opt;
 import "dart:core" as core;
 
-class P<T extends core::Object = core::Object> extends core::Object /*hasConstConstructor*/  {
+class P<T extends core::Object> extends core::Object /*hasConstConstructor*/  {
   final field core::Object token;
   const constructor _(core::Object token) → opt::P<opt::P::T>
     : opt::P::token = token, super core::Object::•()
     ;
 }
-class CP<T extends core::Object = core::Object> extends opt::P<opt::CP::T> /*hasConstConstructor*/  {
+class CP<T extends core::Object> extends opt::P<opt::CP::T> /*hasConstConstructor*/  {
   static final field dynamic _redirecting# = <dynamic>[opt::CP::•]/*isLegacy*/;
   const constructor _(core::Object token) → opt::CP<opt::CP::T>
     : super opt::P::_(token)
     ;
-  static factory •<T extends core::Object = core::Object>(core::Type type) → opt::CP<opt::CP::•::T>
+  static factory •<T extends core::Object>(core::Type type) → opt::CP<opt::CP::•::T>
     let dynamic #redirecting_factory = opt::CP::_ in let opt::CP::•::T #typeArg0 = null in invalid-expression;
 }
-class Token<T extends core::Object = core::Object> extends core::Object /*hasConstConstructor*/  {
+class Token<T extends core::Object> extends core::Object /*hasConstConstructor*/  {
   const constructor •() → opt::Token<opt::Token::T>
     : super core::Object::•()
     ;
 }
-class VP<T extends core::Object = core::Object> extends opt::P<opt::VP::T> /*hasConstConstructor*/  {
+class VP<T extends core::Object> extends opt::P<opt::VP::T> /*hasConstConstructor*/  {
   static final field dynamic _redirecting# = <dynamic>[opt::VP::forToken]/*isLegacy*/;
   const constructor _(core::Object token, opt::VP::T useValue) → opt::VP<opt::VP::T>
     : super opt::P::_(token)
     ;
-  static factory forToken<T extends core::Object = core::Object>(opt::Token<opt::VP::forToken::T> token, opt::VP::forToken::T useValue) → opt::VP<opt::VP::forToken::T>
+  static factory forToken<T extends core::Object>(opt::Token<opt::VP::forToken::T> token, opt::VP::forToken::T useValue) → opt::VP<opt::VP::forToken::T>
     let dynamic #redirecting_factory = opt::VP::_ in let opt::VP::forToken::T #typeArg0 = null in invalid-expression;
 }
 class M extends core::Object /*hasConstConstructor*/  {
diff --git a/pkg/front_end/testcases/nnbd_mixed/object_bound_redirecting_factory/main.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd_mixed/object_bound_redirecting_factory/main.dart.weak.outline.expect
index 95b24a3..06c295f 100644
--- a/pkg/front_end/testcases/nnbd_mixed/object_bound_redirecting_factory/main.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/object_bound_redirecting_factory/main.dart.weak.outline.expect
@@ -43,31 +43,31 @@
 import self as opt;
 import "dart:core" as core;
 
-class P<T extends core::Object = core::Object> extends core::Object /*hasConstConstructor*/  {
+class P<T extends core::Object> extends core::Object /*hasConstConstructor*/  {
   final field core::Object token;
   const constructor _(core::Object token) → opt::P<opt::P::T>
     : opt::P::token = token, super core::Object::•()
     ;
 }
-class CP<T extends core::Object = core::Object> extends opt::P<opt::CP::T> /*hasConstConstructor*/  {
+class CP<T extends core::Object> extends opt::P<opt::CP::T> /*hasConstConstructor*/  {
   static final field dynamic _redirecting# = <dynamic>[opt::CP::•]/*isLegacy*/;
   const constructor _(core::Object token) → opt::CP<opt::CP::T>
     : super opt::P::_(token)
     ;
-  static factory •<T extends core::Object = core::Object>(core::Type type) → opt::CP<opt::CP::•::T>
+  static factory •<T extends core::Object>(core::Type type) → opt::CP<opt::CP::•::T>
     let dynamic #redirecting_factory = opt::CP::_ in let opt::CP::•::T #typeArg0 = null in invalid-expression;
 }
-class Token<T extends core::Object = core::Object> extends core::Object /*hasConstConstructor*/  {
+class Token<T extends core::Object> extends core::Object /*hasConstConstructor*/  {
   const constructor •() → opt::Token<opt::Token::T>
     : super core::Object::•()
     ;
 }
-class VP<T extends core::Object = core::Object> extends opt::P<opt::VP::T> /*hasConstConstructor*/  {
+class VP<T extends core::Object> extends opt::P<opt::VP::T> /*hasConstConstructor*/  {
   static final field dynamic _redirecting# = <dynamic>[opt::VP::forToken]/*isLegacy*/;
   const constructor _(core::Object token, opt::VP::T useValue) → opt::VP<opt::VP::T>
     : super opt::P::_(token)
     ;
-  static factory forToken<T extends core::Object = core::Object>(opt::Token<opt::VP::forToken::T> token, opt::VP::forToken::T useValue) → opt::VP<opt::VP::forToken::T>
+  static factory forToken<T extends core::Object>(opt::Token<opt::VP::forToken::T> token, opt::VP::forToken::T useValue) → opt::VP<opt::VP::forToken::T>
     let dynamic #redirecting_factory = opt::VP::_ in let opt::VP::forToken::T #typeArg0 = null in invalid-expression;
 }
 class M extends core::Object /*hasConstConstructor*/  {
diff --git a/pkg/front_end/testcases/nnbd_mixed/object_bound_redirecting_factory/main.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd_mixed/object_bound_redirecting_factory/main.dart.weak.transformed.expect
index e074504..f4c2c29 100644
--- a/pkg/front_end/testcases/nnbd_mixed/object_bound_redirecting_factory/main.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/object_bound_redirecting_factory/main.dart.weak.transformed.expect
@@ -43,31 +43,31 @@
 import self as opt;
 import "dart:core" as core;
 
-class P<T extends core::Object = core::Object> extends core::Object /*hasConstConstructor*/  {
+class P<T extends core::Object> extends core::Object /*hasConstConstructor*/  {
   final field core::Object token;
   const constructor _(core::Object token) → opt::P<opt::P::T>
     : opt::P::token = token, super core::Object::•()
     ;
 }
-class CP<T extends core::Object = core::Object> extends opt::P<opt::CP::T> /*hasConstConstructor*/  {
+class CP<T extends core::Object> extends opt::P<opt::CP::T> /*hasConstConstructor*/  {
   static final field dynamic _redirecting# = <dynamic>[opt::CP::•]/*isLegacy*/;
   const constructor _(core::Object token) → opt::CP<opt::CP::T>
     : super opt::P::_(token)
     ;
-  static factory •<T extends core::Object = core::Object>(core::Type type) → opt::CP<opt::CP::•::T>
+  static factory •<T extends core::Object>(core::Type type) → opt::CP<opt::CP::•::T>
     let Never #redirecting_factory = opt::CP::_ in let opt::CP::•::T #typeArg0 = null in invalid-expression;
 }
-class Token<T extends core::Object = core::Object> extends core::Object /*hasConstConstructor*/  {
+class Token<T extends core::Object> extends core::Object /*hasConstConstructor*/  {
   const constructor •() → opt::Token<opt::Token::T>
     : super core::Object::•()
     ;
 }
-class VP<T extends core::Object = core::Object> extends opt::P<opt::VP::T> /*hasConstConstructor*/  {
+class VP<T extends core::Object> extends opt::P<opt::VP::T> /*hasConstConstructor*/  {
   static final field dynamic _redirecting# = <dynamic>[opt::VP::forToken]/*isLegacy*/;
   const constructor _(core::Object token, opt::VP::T useValue) → opt::VP<opt::VP::T>
     : super opt::P::_(token)
     ;
-  static factory forToken<T extends core::Object = core::Object>(opt::Token<opt::VP::forToken::T> token, opt::VP::forToken::T useValue) → opt::VP<opt::VP::forToken::T>
+  static factory forToken<T extends core::Object>(opt::Token<opt::VP::forToken::T> token, opt::VP::forToken::T useValue) → opt::VP<opt::VP::forToken::T>
     let Never #redirecting_factory = opt::VP::_ in let opt::VP::forToken::T #typeArg0 = null in invalid-expression;
 }
 class M extends core::Object /*hasConstConstructor*/  {
diff --git a/pkg/front_end/testcases/nnbd_mixed/super_access/main.dart.weak.expect b/pkg/front_end/testcases/nnbd_mixed/super_access/main.dart.weak.expect
index ca14755..6bf247e 100644
--- a/pkg/front_end/testcases/nnbd_mixed/super_access/main.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/super_access/main.dart.weak.expect
@@ -98,13 +98,13 @@
 import self as mai2;
 import "dart:core" as core;
 
-typedef Typedef<unrelated T extends mai2::Value<dynamic> = mai2::Value<dynamic>, contravariant I extends core::Object? = dynamic> = (I%) → core::Type;
+typedef Typedef<unrelated T extends mai2::Value<dynamic>, contravariant I extends core::Object? = dynamic> = (I%) → core::Type;
 abstract class Value<T extends core::Object? = dynamic> extends core::Object {
   synthetic constructor •() → mai2::Value<mai2::Value::T%>
     : super core::Object::•()
     ;
 }
-class Interface<T extends mai2::Value<dynamic> = mai2::Value<dynamic>, I extends core::Object? = dynamic> extends core::Object {
+class Interface<T extends mai2::Value<dynamic>, I extends core::Object? = dynamic> extends core::Object {
   field (mai2::Interface::I%) →? core::Type field = null;
   synthetic constructor •() → mai2::Interface<mai2::Interface::T, mai2::Interface::I%>
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/nnbd_mixed/super_access/main.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd_mixed/super_access/main.dart.weak.outline.expect
index ec066e1..7f83539 100644
--- a/pkg/front_end/testcases/nnbd_mixed/super_access/main.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/super_access/main.dart.weak.outline.expect
@@ -93,12 +93,12 @@
 import self as mai2;
 import "dart:core" as core;
 
-typedef Typedef<unrelated T extends mai2::Value<dynamic> = mai2::Value<dynamic>, contravariant I extends core::Object? = dynamic> = (I%) → core::Type;
+typedef Typedef<unrelated T extends mai2::Value<dynamic>, contravariant I extends core::Object? = dynamic> = (I%) → core::Type;
 abstract class Value<T extends core::Object? = dynamic> extends core::Object {
   synthetic constructor •() → mai2::Value<mai2::Value::T%>
     ;
 }
-class Interface<T extends mai2::Value<dynamic> = mai2::Value<dynamic>, I extends core::Object? = dynamic> extends core::Object {
+class Interface<T extends mai2::Value<dynamic>, I extends core::Object? = dynamic> extends core::Object {
   field (mai2::Interface::I%) →? core::Type field;
   synthetic constructor •() → mai2::Interface<mai2::Interface::T, mai2::Interface::I%>
     ;
diff --git a/pkg/front_end/testcases/nnbd_mixed/super_access/main.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd_mixed/super_access/main.dart.weak.transformed.expect
index 7f96d00..2a72e6a 100644
--- a/pkg/front_end/testcases/nnbd_mixed/super_access/main.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/super_access/main.dart.weak.transformed.expect
@@ -94,13 +94,13 @@
 import self as mai2;
 import "dart:core" as core;
 
-typedef Typedef<unrelated T extends mai2::Value<dynamic> = mai2::Value<dynamic>, contravariant I extends core::Object? = dynamic> = (I%) → core::Type;
+typedef Typedef<unrelated T extends mai2::Value<dynamic>, contravariant I extends core::Object? = dynamic> = (I%) → core::Type;
 abstract class Value<T extends core::Object? = dynamic> extends core::Object {
   synthetic constructor •() → mai2::Value<mai2::Value::T%>
     : super core::Object::•()
     ;
 }
-class Interface<T extends mai2::Value<dynamic> = mai2::Value<dynamic>, I extends core::Object? = dynamic> extends core::Object {
+class Interface<T extends mai2::Value<dynamic>, I extends core::Object? = dynamic> extends core::Object {
   field (mai2::Interface::I%) →? core::Type field = null;
   synthetic constructor •() → mai2::Interface<mai2::Interface::T, mai2::Interface::I%>
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/nnbd_mixed/super_access/main.no_link.dart.weak.expect b/pkg/front_end/testcases/nnbd_mixed/super_access/main.no_link.dart.weak.expect
index ca14755..6bf247e 100644
--- a/pkg/front_end/testcases/nnbd_mixed/super_access/main.no_link.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/super_access/main.no_link.dart.weak.expect
@@ -98,13 +98,13 @@
 import self as mai2;
 import "dart:core" as core;
 
-typedef Typedef<unrelated T extends mai2::Value<dynamic> = mai2::Value<dynamic>, contravariant I extends core::Object? = dynamic> = (I%) → core::Type;
+typedef Typedef<unrelated T extends mai2::Value<dynamic>, contravariant I extends core::Object? = dynamic> = (I%) → core::Type;
 abstract class Value<T extends core::Object? = dynamic> extends core::Object {
   synthetic constructor •() → mai2::Value<mai2::Value::T%>
     : super core::Object::•()
     ;
 }
-class Interface<T extends mai2::Value<dynamic> = mai2::Value<dynamic>, I extends core::Object? = dynamic> extends core::Object {
+class Interface<T extends mai2::Value<dynamic>, I extends core::Object? = dynamic> extends core::Object {
   field (mai2::Interface::I%) →? core::Type field = null;
   synthetic constructor •() → mai2::Interface<mai2::Interface::T, mai2::Interface::I%>
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/nnbd_mixed/super_access/main.no_link.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd_mixed/super_access/main.no_link.dart.weak.outline.expect
index ec066e1..7f83539 100644
--- a/pkg/front_end/testcases/nnbd_mixed/super_access/main.no_link.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/super_access/main.no_link.dart.weak.outline.expect
@@ -93,12 +93,12 @@
 import self as mai2;
 import "dart:core" as core;
 
-typedef Typedef<unrelated T extends mai2::Value<dynamic> = mai2::Value<dynamic>, contravariant I extends core::Object? = dynamic> = (I%) → core::Type;
+typedef Typedef<unrelated T extends mai2::Value<dynamic>, contravariant I extends core::Object? = dynamic> = (I%) → core::Type;
 abstract class Value<T extends core::Object? = dynamic> extends core::Object {
   synthetic constructor •() → mai2::Value<mai2::Value::T%>
     ;
 }
-class Interface<T extends mai2::Value<dynamic> = mai2::Value<dynamic>, I extends core::Object? = dynamic> extends core::Object {
+class Interface<T extends mai2::Value<dynamic>, I extends core::Object? = dynamic> extends core::Object {
   field (mai2::Interface::I%) →? core::Type field;
   synthetic constructor •() → mai2::Interface<mai2::Interface::T, mai2::Interface::I%>
     ;
diff --git a/pkg/front_end/testcases/nnbd_mixed/super_access/main.no_link.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd_mixed/super_access/main.no_link.dart.weak.transformed.expect
index 7f96d00..2a72e6a 100644
--- a/pkg/front_end/testcases/nnbd_mixed/super_access/main.no_link.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/super_access/main.no_link.dart.weak.transformed.expect
@@ -94,13 +94,13 @@
 import self as mai2;
 import "dart:core" as core;
 
-typedef Typedef<unrelated T extends mai2::Value<dynamic> = mai2::Value<dynamic>, contravariant I extends core::Object? = dynamic> = (I%) → core::Type;
+typedef Typedef<unrelated T extends mai2::Value<dynamic>, contravariant I extends core::Object? = dynamic> = (I%) → core::Type;
 abstract class Value<T extends core::Object? = dynamic> extends core::Object {
   synthetic constructor •() → mai2::Value<mai2::Value::T%>
     : super core::Object::•()
     ;
 }
-class Interface<T extends mai2::Value<dynamic> = mai2::Value<dynamic>, I extends core::Object? = dynamic> extends core::Object {
+class Interface<T extends mai2::Value<dynamic>, I extends core::Object? = dynamic> extends core::Object {
   field (mai2::Interface::I%) →? core::Type field = null;
   synthetic constructor •() → mai2::Interface<mai2::Interface::T, mai2::Interface::I%>
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/nnbd_mixed/type_parameter_nullability.dart.weak.expect b/pkg/front_end/testcases/nnbd_mixed/type_parameter_nullability.dart.weak.expect
index 8bf95a6..cd3de48 100644
--- a/pkg/front_end/testcases/nnbd_mixed/type_parameter_nullability.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/type_parameter_nullability.dart.weak.expect
@@ -5,7 +5,7 @@
 
 import "org-dartlang-testcase:///type_parameter_nullability_lib.dart";
 
-class C<T extends core::num? = core::num?, S extends core::Object? = dynamic, U extends core::Object? = dynamic> extends core::Object {
+class C<T extends core::num?, S extends core::Object? = dynamic, U extends core::Object? = dynamic> extends core::Object {
   synthetic constructor •() → self::C<self::C::T%, self::C::S%, self::C::U%>
     : super core::Object::•()
     ;
@@ -36,7 +36,7 @@
 import self as typ;
 import "dart:core" as core;
 
-class D<T extends core::num* = core::num*> extends core::Object {
+class D<T extends core::num*> extends core::Object {
   synthetic constructor •() → typ::D<typ::D::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nnbd_mixed/type_parameter_nullability.dart.weak.outline.expect b/pkg/front_end/testcases/nnbd_mixed/type_parameter_nullability.dart.weak.outline.expect
index ffb28dc..ef4392a 100644
--- a/pkg/front_end/testcases/nnbd_mixed/type_parameter_nullability.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/type_parameter_nullability.dart.weak.outline.expect
@@ -4,7 +4,7 @@
 
 import "org-dartlang-testcase:///type_parameter_nullability_lib.dart";
 
-class C<T extends core::num? = core::num?, S extends core::Object? = dynamic, U extends core::Object? = dynamic> extends core::Object {
+class C<T extends core::num?, S extends core::Object? = dynamic, U extends core::Object? = dynamic> extends core::Object {
   synthetic constructor •() → self::C<self::C::T%, self::C::S%, self::C::U%>
     ;
   method promoteNullable(generic-covariant-impl self::C::T? t) → void
@@ -19,7 +19,7 @@
 import self as self2;
 import "dart:core" as core;
 
-class D<T extends core::num* = core::num*> extends core::Object {
+class D<T extends core::num*> extends core::Object {
   synthetic constructor •() → self2::D<self2::D::T*>*
     ;
   method promoteLegacy(generic-covariant-impl self2::D::T* t) → void
diff --git a/pkg/front_end/testcases/nnbd_mixed/type_parameter_nullability.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd_mixed/type_parameter_nullability.dart.weak.transformed.expect
index 8bf95a6..cd3de48 100644
--- a/pkg/front_end/testcases/nnbd_mixed/type_parameter_nullability.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/type_parameter_nullability.dart.weak.transformed.expect
@@ -5,7 +5,7 @@
 
 import "org-dartlang-testcase:///type_parameter_nullability_lib.dart";
 
-class C<T extends core::num? = core::num?, S extends core::Object? = dynamic, U extends core::Object? = dynamic> extends core::Object {
+class C<T extends core::num?, S extends core::Object? = dynamic, U extends core::Object? = dynamic> extends core::Object {
   synthetic constructor •() → self::C<self::C::T%, self::C::S%, self::C::U%>
     : super core::Object::•()
     ;
@@ -36,7 +36,7 @@
 import self as typ;
 import "dart:core" as core;
 
-class D<T extends core::num* = core::num*> extends core::Object {
+class D<T extends core::num*> extends core::Object {
   synthetic constructor •() → typ::D<typ::D::T*>*
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/none/equals.dart.strong.expect b/pkg/front_end/testcases/none/equals.dart.strong.expect
index 3c8e61d..daaf5db 100644
--- a/pkg/front_end/testcases/none/equals.dart.strong.expect
+++ b/pkg/front_end/testcases/none/equals.dart.strong.expect
@@ -126,7 +126,7 @@
   method method(dynamic o) → dynamic {}
 }
 static const field core::Object? nullValue = #C1;
-static method test<T1 extends core::Function = core::Function, T2 extends (core::int) → core::int = (core::int) → core::int>(core::Object o, core::Object nonNullableObject, core::Object? nullableObject, self::Class<core::String> nonNullableClass, self::Class<core::String>? nullableClass, dynamic dyn, Never never, Never? nullableNever, Null nullTypedValue, core::Function nonNullableFunction, core::Function? nullableFunction, (core::int) → core::int nonNullableFunctionType, (core::int) →? core::int nullableFunctionType, self::test::T1 nonNullableTypeVariable1, self::test::T1? nullableTypeVariable1, self::test::T2 nonNullableTypeVariable2, self::test::T2? nullableTypeVariable2) → dynamic {
+static method test<T1 extends core::Function, T2 extends (core::int) → core::int>(core::Object o, core::Object nonNullableObject, core::Object? nullableObject, self::Class<core::String> nonNullableClass, self::Class<core::String>? nullableClass, dynamic dyn, Never never, Never? nullableNever, Null nullTypedValue, core::Function nonNullableFunction, core::Function? nullableFunction, (core::int) → core::int nonNullableFunctionType, (core::int) →? core::int nullableFunctionType, self::test::T1 nonNullableTypeVariable1, self::test::T1? nullableTypeVariable1, self::test::T2 nonNullableTypeVariable2, self::test::T2? nullableTypeVariable2) → dynamic {
   core::print("EqualsNull (literal null)");
   null == null;
   !(null == null);
diff --git a/pkg/front_end/testcases/none/equals.dart.weak.expect b/pkg/front_end/testcases/none/equals.dart.weak.expect
index 622fa6c8..5b4129e 100644
--- a/pkg/front_end/testcases/none/equals.dart.weak.expect
+++ b/pkg/front_end/testcases/none/equals.dart.weak.expect
@@ -127,7 +127,7 @@
   method method(dynamic o) → dynamic {}
 }
 static const field core::Object? nullValue = #C1;
-static method test<T1 extends core::Function = core::Function, T2 extends (core::int) → core::int = (core::int) → core::int>(core::Object o, core::Object nonNullableObject, core::Object? nullableObject, self::Class<core::String> nonNullableClass, self::Class<core::String>? nullableClass, dynamic dyn, Never never, Never? nullableNever, Null nullTypedValue, core::Function nonNullableFunction, core::Function? nullableFunction, (core::int) → core::int nonNullableFunctionType, (core::int) →? core::int nullableFunctionType, self::test::T1 nonNullableTypeVariable1, self::test::T1? nullableTypeVariable1, self::test::T2 nonNullableTypeVariable2, self::test::T2? nullableTypeVariable2) → dynamic {
+static method test<T1 extends core::Function, T2 extends (core::int) → core::int>(core::Object o, core::Object nonNullableObject, core::Object? nullableObject, self::Class<core::String> nonNullableClass, self::Class<core::String>? nullableClass, dynamic dyn, Never never, Never? nullableNever, Null nullTypedValue, core::Function nonNullableFunction, core::Function? nullableFunction, (core::int) → core::int nonNullableFunctionType, (core::int) →? core::int nullableFunctionType, self::test::T1 nonNullableTypeVariable1, self::test::T1? nullableTypeVariable1, self::test::T2 nonNullableTypeVariable2, self::test::T2? nullableTypeVariable2) → dynamic {
   core::print("EqualsNull (literal null)");
   null == null;
   !(null == null);
diff --git a/pkg/front_end/testcases/none/equals.dart.weak.outline.expect b/pkg/front_end/testcases/none/equals.dart.weak.outline.expect
index aae3b91..911e7cd 100644
--- a/pkg/front_end/testcases/none/equals.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/none/equals.dart.weak.outline.expect
@@ -11,7 +11,7 @@
     ;
 }
 static const field core::Object? nullValue = null;
-static method test<T1 extends core::Function = core::Function, T2 extends (core::int) → core::int = (core::int) → core::int>(core::Object o, core::Object nonNullableObject, core::Object? nullableObject, self::Class<core::String> nonNullableClass, self::Class<core::String>? nullableClass, dynamic dyn, Never never, Never? nullableNever, Null nullTypedValue, core::Function nonNullableFunction, core::Function? nullableFunction, (core::int) → core::int nonNullableFunctionType, (core::int) →? core::int nullableFunctionType, self::test::T1 nonNullableTypeVariable1, self::test::T1? nullableTypeVariable1, self::test::T2 nonNullableTypeVariable2, self::test::T2? nullableTypeVariable2) → dynamic
+static method test<T1 extends core::Function, T2 extends (core::int) → core::int>(core::Object o, core::Object nonNullableObject, core::Object? nullableObject, self::Class<core::String> nonNullableClass, self::Class<core::String>? nullableClass, dynamic dyn, Never never, Never? nullableNever, Null nullTypedValue, core::Function nonNullableFunction, core::Function? nullableFunction, (core::int) → core::int nonNullableFunctionType, (core::int) →? core::int nullableFunctionType, self::test::T1 nonNullableTypeVariable1, self::test::T1? nullableTypeVariable1, self::test::T2 nonNullableTypeVariable2, self::test::T2? nullableTypeVariable2) → dynamic
   ;
 static method nullEqualsIndexGet(core::Map<core::int, core::String> map) → dynamic
   ;
diff --git a/pkg/front_end/testcases/none/method_invocation.dart.strong.expect b/pkg/front_end/testcases/none/method_invocation.dart.strong.expect
index d1046ad..32d8252 100644
--- a/pkg/front_end/testcases/none/method_invocation.dart.strong.expect
+++ b/pkg/front_end/testcases/none/method_invocation.dart.strong.expect
@@ -135,7 +135,7 @@
 static const field core::int i = #C1;
 static const field core::int j = #C2;
 static const field core::int k = #C3;
-static method test<T1 extends core::Function = core::Function, T2 extends (core::int) → core::int = (core::int) → core::int, T3 extends core::Object? = dynamic>(self::Class1 nonNullableClass1, self::Class1? nullableClass1, dynamic dyn, Never never, self::Class2<core::String> nonNullableClass2, self::Class2<core::String>? nullableClass2, core::Function nonNullableFunction, core::Function? nullableFunction, (core::int) → core::int nonNullableFunctionType, (core::int) →? core::int nullableFunctionType, <T extends core::Object? = dynamic>(T%) → T% genericFunctionType, self::test::T1 nonNullableTypeVariable1, self::test::T1? nullableTypeVariable1, self::test::T2 nonNullableTypeVariable2, self::test::T2? nullableTypeVariable2, self::test::T3% undeterminedTypeVariable) → dynamic {
+static method test<T1 extends core::Function, T2 extends (core::int) → core::int, T3 extends core::Object? = dynamic>(self::Class1 nonNullableClass1, self::Class1? nullableClass1, dynamic dyn, Never never, self::Class2<core::String> nonNullableClass2, self::Class2<core::String>? nullableClass2, core::Function nonNullableFunction, core::Function? nullableFunction, (core::int) → core::int nonNullableFunctionType, (core::int) →? core::int nullableFunctionType, <T extends core::Object? = dynamic>(T%) → T% genericFunctionType, self::test::T1 nonNullableTypeVariable1, self::test::T1? nullableTypeVariable1, self::test::T2 nonNullableTypeVariable2, self::test::T2? nullableTypeVariable2, self::test::T3% undeterminedTypeVariable) → dynamic {
   core::print("InstanceInvocation");
   nonNullableClass1.{self::Class1::method}(0){(core::int) → core::double};
   let final self::Class1? #t1 = nullableClass1 in #t1 == null ?{core::double?} null : #t1{self::Class1}.{self::Class1::method}(0){(core::int) → core::double};
diff --git a/pkg/front_end/testcases/none/method_invocation.dart.weak.expect b/pkg/front_end/testcases/none/method_invocation.dart.weak.expect
index 436611c..0f57fe6 100644
--- a/pkg/front_end/testcases/none/method_invocation.dart.weak.expect
+++ b/pkg/front_end/testcases/none/method_invocation.dart.weak.expect
@@ -136,7 +136,7 @@
 static const field core::int i = #C1;
 static const field core::int j = #C2;
 static const field core::int k = #C3;
-static method test<T1 extends core::Function = core::Function, T2 extends (core::int) → core::int = (core::int) → core::int, T3 extends core::Object? = dynamic>(self::Class1 nonNullableClass1, self::Class1? nullableClass1, dynamic dyn, Never never, self::Class2<core::String> nonNullableClass2, self::Class2<core::String>? nullableClass2, core::Function nonNullableFunction, core::Function? nullableFunction, (core::int) → core::int nonNullableFunctionType, (core::int) →? core::int nullableFunctionType, <T extends core::Object? = dynamic>(T%) → T% genericFunctionType, self::test::T1 nonNullableTypeVariable1, self::test::T1? nullableTypeVariable1, self::test::T2 nonNullableTypeVariable2, self::test::T2? nullableTypeVariable2, self::test::T3% undeterminedTypeVariable) → dynamic {
+static method test<T1 extends core::Function, T2 extends (core::int) → core::int, T3 extends core::Object? = dynamic>(self::Class1 nonNullableClass1, self::Class1? nullableClass1, dynamic dyn, Never never, self::Class2<core::String> nonNullableClass2, self::Class2<core::String>? nullableClass2, core::Function nonNullableFunction, core::Function? nullableFunction, (core::int) → core::int nonNullableFunctionType, (core::int) →? core::int nullableFunctionType, <T extends core::Object? = dynamic>(T%) → T% genericFunctionType, self::test::T1 nonNullableTypeVariable1, self::test::T1? nullableTypeVariable1, self::test::T2 nonNullableTypeVariable2, self::test::T2? nullableTypeVariable2, self::test::T3% undeterminedTypeVariable) → dynamic {
   core::print("InstanceInvocation");
   nonNullableClass1.{self::Class1::method}(0){(core::int) → core::double};
   let final self::Class1? #t1 = nullableClass1 in #t1 == null ?{core::double?} null : #t1{self::Class1}.{self::Class1::method}(0){(core::int) → core::double};
diff --git a/pkg/front_end/testcases/none/method_invocation.dart.weak.outline.expect b/pkg/front_end/testcases/none/method_invocation.dart.weak.outline.expect
index 8a7fc69..7358160 100644
--- a/pkg/front_end/testcases/none/method_invocation.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/none/method_invocation.dart.weak.outline.expect
@@ -32,7 +32,7 @@
 static const field core::int i = 4;
 static const field core::int j = 24;
 static const field core::int k = self::i.{core::num::*}(self::j){(core::num) → core::int};
-static method test<T1 extends core::Function = core::Function, T2 extends (core::int) → core::int = (core::int) → core::int, T3 extends core::Object? = dynamic>(self::Class1 nonNullableClass1, self::Class1? nullableClass1, dynamic dyn, Never never, self::Class2<core::String> nonNullableClass2, self::Class2<core::String>? nullableClass2, core::Function nonNullableFunction, core::Function? nullableFunction, (core::int) → core::int nonNullableFunctionType, (core::int) →? core::int nullableFunctionType, <T extends core::Object? = dynamic>(T%) → T% genericFunctionType, self::test::T1 nonNullableTypeVariable1, self::test::T1? nullableTypeVariable1, self::test::T2 nonNullableTypeVariable2, self::test::T2? nullableTypeVariable2, self::test::T3% undeterminedTypeVariable) → dynamic
+static method test<T1 extends core::Function, T2 extends (core::int) → core::int, T3 extends core::Object? = dynamic>(self::Class1 nonNullableClass1, self::Class1? nullableClass1, dynamic dyn, Never never, self::Class2<core::String> nonNullableClass2, self::Class2<core::String>? nullableClass2, core::Function nonNullableFunction, core::Function? nullableFunction, (core::int) → core::int nonNullableFunctionType, (core::int) →? core::int nullableFunctionType, <T extends core::Object? = dynamic>(T%) → T% genericFunctionType, self::test::T1 nonNullableTypeVariable1, self::test::T1? nullableTypeVariable1, self::test::T2 nonNullableTypeVariable2, self::test::T2? nullableTypeVariable2, self::test::T3% undeterminedTypeVariable) → dynamic
   ;
 static method main() → dynamic
   ;
diff --git a/pkg/front_end/testcases/none/property_get.dart.strong.expect b/pkg/front_end/testcases/none/property_get.dart.strong.expect
index b753715..921ff16 100644
--- a/pkg/front_end/testcases/none/property_get.dart.strong.expect
+++ b/pkg/front_end/testcases/none/property_get.dart.strong.expect
@@ -61,7 +61,7 @@
 static const field core::int dynamicStringLength = #C2;
 static method topLevelMethod(core::double o) → core::int
   return 0;
-static method test<T1 extends core::Function = core::Function, T2 extends () → core::int = () → core::int>(self::Class1 nonNullableClass1, self::Class1? nullableClass1, dynamic dyn, Never never, self::Class2<core::String> nonNullableClass2, self::Class2<core::String>? nullableClass2, core::Function nonNullableFunction, core::Function? nullableFunction, () → core::int nonNullableFunctionType, () →? core::int nullableFunctionType, self::test::T1 nonNullableTypeVariable1, self::test::T1? nullableTypeVariable1, self::test::T2 nonNullableTypeVariable2, self::test::T2? nullableTypeVariable2) → dynamic {
+static method test<T1 extends core::Function, T2 extends () → core::int>(self::Class1 nonNullableClass1, self::Class1? nullableClass1, dynamic dyn, Never never, self::Class2<core::String> nonNullableClass2, self::Class2<core::String>? nullableClass2, core::Function nonNullableFunction, core::Function? nullableFunction, () → core::int nonNullableFunctionType, () →? core::int nullableFunctionType, self::test::T1 nonNullableTypeVariable1, self::test::T1? nullableTypeVariable1, self::test::T2 nonNullableTypeVariable2, self::test::T2? nullableTypeVariable2) → dynamic {
   core::print("InstanceGet");
   nonNullableClass1.{self::Class1::field}{core::int};
   let final self::Class1? #t1 = nullableClass1 in #t1 == null ?{core::int?} null : #t1{self::Class1}.{self::Class1::field}{core::int};
diff --git a/pkg/front_end/testcases/none/property_get.dart.weak.expect b/pkg/front_end/testcases/none/property_get.dart.weak.expect
index db37697..67ded25 100644
--- a/pkg/front_end/testcases/none/property_get.dart.weak.expect
+++ b/pkg/front_end/testcases/none/property_get.dart.weak.expect
@@ -62,7 +62,7 @@
 static const field core::int dynamicStringLength = #C2;
 static method topLevelMethod(core::double o) → core::int
   return 0;
-static method test<T1 extends core::Function = core::Function, T2 extends () → core::int = () → core::int>(self::Class1 nonNullableClass1, self::Class1? nullableClass1, dynamic dyn, Never never, self::Class2<core::String> nonNullableClass2, self::Class2<core::String>? nullableClass2, core::Function nonNullableFunction, core::Function? nullableFunction, () → core::int nonNullableFunctionType, () →? core::int nullableFunctionType, self::test::T1 nonNullableTypeVariable1, self::test::T1? nullableTypeVariable1, self::test::T2 nonNullableTypeVariable2, self::test::T2? nullableTypeVariable2) → dynamic {
+static method test<T1 extends core::Function, T2 extends () → core::int>(self::Class1 nonNullableClass1, self::Class1? nullableClass1, dynamic dyn, Never never, self::Class2<core::String> nonNullableClass2, self::Class2<core::String>? nullableClass2, core::Function nonNullableFunction, core::Function? nullableFunction, () → core::int nonNullableFunctionType, () →? core::int nullableFunctionType, self::test::T1 nonNullableTypeVariable1, self::test::T1? nullableTypeVariable1, self::test::T2 nonNullableTypeVariable2, self::test::T2? nullableTypeVariable2) → dynamic {
   core::print("InstanceGet");
   nonNullableClass1.{self::Class1::field}{core::int};
   let final self::Class1? #t1 = nullableClass1 in #t1 == null ?{core::int?} null : #t1{self::Class1}.{self::Class1::field}{core::int};
diff --git a/pkg/front_end/testcases/none/property_get.dart.weak.outline.expect b/pkg/front_end/testcases/none/property_get.dart.weak.outline.expect
index 06c8396..fcd26f0 100644
--- a/pkg/front_end/testcases/none/property_get.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/none/property_get.dart.weak.outline.expect
@@ -26,7 +26,7 @@
 static const field core::int dynamicStringLength = self::dynamicString{dynamic}.length as{TypeError,ForDynamic,ForNonNullableByDefault} core::int;
 static method topLevelMethod(core::double o) → core::int
   ;
-static method test<T1 extends core::Function = core::Function, T2 extends () → core::int = () → core::int>(self::Class1 nonNullableClass1, self::Class1? nullableClass1, dynamic dyn, Never never, self::Class2<core::String> nonNullableClass2, self::Class2<core::String>? nullableClass2, core::Function nonNullableFunction, core::Function? nullableFunction, () → core::int nonNullableFunctionType, () →? core::int nullableFunctionType, self::test::T1 nonNullableTypeVariable1, self::test::T1? nullableTypeVariable1, self::test::T2 nonNullableTypeVariable2, self::test::T2? nullableTypeVariable2) → dynamic
+static method test<T1 extends core::Function, T2 extends () → core::int>(self::Class1 nonNullableClass1, self::Class1? nullableClass1, dynamic dyn, Never never, self::Class2<core::String> nonNullableClass2, self::Class2<core::String>? nullableClass2, core::Function nonNullableFunction, core::Function? nullableFunction, () → core::int nonNullableFunctionType, () →? core::int nullableFunctionType, self::test::T1 nonNullableTypeVariable1, self::test::T1? nullableTypeVariable1, self::test::T2 nonNullableTypeVariable2, self::test::T2? nullableTypeVariable2) → dynamic
   ;
 static method main() → dynamic
   ;
diff --git a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks.dart.strong.expect b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks.dart.strong.expect
index 7506643..68d1353 100644
--- a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks.dart.strong.expect
+++ b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks.dart.strong.expect
@@ -175,7 +175,7 @@
     : super core::Object::•()
     ;
 }
-class Bar1<X extends self::A<self::A<core::int>> = self::A<self::A<core::int>>> extends core::Object {
+class Bar1<X extends self::A<self::A<core::int>>> extends core::Object {
   synthetic constructor •() → self::Bar1<self::Bar1::X>
     : super core::Object::•()
     ;
@@ -183,10 +183,10 @@
     return throw 42;
   method barBar12(self::A<self::A<core::int>> x) → dynamic
     return throw 42;
-  method barBar13<X extends self::A<self::A<core::int>> = self::A<self::A<core::int>>>() → dynamic
+  method barBar13<X extends self::A<self::A<core::int>>>() → dynamic
     return throw 42;
 }
-class Bar2<X extends self::A<self::A<self::A<core::int>>> = self::A<self::A<self::A<core::int>>>> extends core::Object {
+class Bar2<X extends self::A<self::A<self::A<core::int>>>> extends core::Object {
   synthetic constructor •() → self::Bar2<self::Bar2::X>
     : super core::Object::•()
     ;
@@ -194,7 +194,7 @@
     return throw 42;
   method barBar22(self::A<self::A<self::A<core::int>>> x) → dynamic
     return throw 42;
-  method barBar23<X extends self::A<self::A<self::A<core::int>>> = self::A<self::A<self::A<core::int>>>>() → dynamic
+  method barBar23<X extends self::A<self::A<self::A<core::int>>>>() → dynamic
     return throw 42;
 }
 static method foo() → dynamic {
@@ -209,8 +209,8 @@
   return throw 42;
 static method bar2b(self::A<self::A<self::A<core::int>>> x) → dynamic
   return throw 42;
-static method bar3a<X extends self::A<self::A<core::int>> = self::A<self::A<core::int>>>() → dynamic
+static method bar3a<X extends self::A<self::A<core::int>>>() → dynamic
   return throw 42;
-static method bar3b<X extends self::A<self::A<self::A<core::int>>> = self::A<self::A<self::A<core::int>>>>() → dynamic
+static method bar3b<X extends self::A<self::A<self::A<core::int>>>>() → dynamic
   return throw 42;
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks.dart.strong.transformed.expect b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks.dart.strong.transformed.expect
index 7506643..68d1353 100644
--- a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks.dart.strong.transformed.expect
@@ -175,7 +175,7 @@
     : super core::Object::•()
     ;
 }
-class Bar1<X extends self::A<self::A<core::int>> = self::A<self::A<core::int>>> extends core::Object {
+class Bar1<X extends self::A<self::A<core::int>>> extends core::Object {
   synthetic constructor •() → self::Bar1<self::Bar1::X>
     : super core::Object::•()
     ;
@@ -183,10 +183,10 @@
     return throw 42;
   method barBar12(self::A<self::A<core::int>> x) → dynamic
     return throw 42;
-  method barBar13<X extends self::A<self::A<core::int>> = self::A<self::A<core::int>>>() → dynamic
+  method barBar13<X extends self::A<self::A<core::int>>>() → dynamic
     return throw 42;
 }
-class Bar2<X extends self::A<self::A<self::A<core::int>>> = self::A<self::A<self::A<core::int>>>> extends core::Object {
+class Bar2<X extends self::A<self::A<self::A<core::int>>>> extends core::Object {
   synthetic constructor •() → self::Bar2<self::Bar2::X>
     : super core::Object::•()
     ;
@@ -194,7 +194,7 @@
     return throw 42;
   method barBar22(self::A<self::A<self::A<core::int>>> x) → dynamic
     return throw 42;
-  method barBar23<X extends self::A<self::A<self::A<core::int>>> = self::A<self::A<self::A<core::int>>>>() → dynamic
+  method barBar23<X extends self::A<self::A<self::A<core::int>>>>() → dynamic
     return throw 42;
 }
 static method foo() → dynamic {
@@ -209,8 +209,8 @@
   return throw 42;
 static method bar2b(self::A<self::A<self::A<core::int>>> x) → dynamic
   return throw 42;
-static method bar3a<X extends self::A<self::A<core::int>> = self::A<self::A<core::int>>>() → dynamic
+static method bar3a<X extends self::A<self::A<core::int>>>() → dynamic
   return throw 42;
-static method bar3b<X extends self::A<self::A<self::A<core::int>>> = self::A<self::A<self::A<core::int>>>>() → dynamic
+static method bar3b<X extends self::A<self::A<self::A<core::int>>>>() → dynamic
   return throw 42;
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks.dart.weak.expect b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks.dart.weak.expect
index 7506643..68d1353 100644
--- a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks.dart.weak.expect
+++ b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks.dart.weak.expect
@@ -175,7 +175,7 @@
     : super core::Object::•()
     ;
 }
-class Bar1<X extends self::A<self::A<core::int>> = self::A<self::A<core::int>>> extends core::Object {
+class Bar1<X extends self::A<self::A<core::int>>> extends core::Object {
   synthetic constructor •() → self::Bar1<self::Bar1::X>
     : super core::Object::•()
     ;
@@ -183,10 +183,10 @@
     return throw 42;
   method barBar12(self::A<self::A<core::int>> x) → dynamic
     return throw 42;
-  method barBar13<X extends self::A<self::A<core::int>> = self::A<self::A<core::int>>>() → dynamic
+  method barBar13<X extends self::A<self::A<core::int>>>() → dynamic
     return throw 42;
 }
-class Bar2<X extends self::A<self::A<self::A<core::int>>> = self::A<self::A<self::A<core::int>>>> extends core::Object {
+class Bar2<X extends self::A<self::A<self::A<core::int>>>> extends core::Object {
   synthetic constructor •() → self::Bar2<self::Bar2::X>
     : super core::Object::•()
     ;
@@ -194,7 +194,7 @@
     return throw 42;
   method barBar22(self::A<self::A<self::A<core::int>>> x) → dynamic
     return throw 42;
-  method barBar23<X extends self::A<self::A<self::A<core::int>>> = self::A<self::A<self::A<core::int>>>>() → dynamic
+  method barBar23<X extends self::A<self::A<self::A<core::int>>>>() → dynamic
     return throw 42;
 }
 static method foo() → dynamic {
@@ -209,8 +209,8 @@
   return throw 42;
 static method bar2b(self::A<self::A<self::A<core::int>>> x) → dynamic
   return throw 42;
-static method bar3a<X extends self::A<self::A<core::int>> = self::A<self::A<core::int>>>() → dynamic
+static method bar3a<X extends self::A<self::A<core::int>>>() → dynamic
   return throw 42;
-static method bar3b<X extends self::A<self::A<self::A<core::int>>> = self::A<self::A<self::A<core::int>>>>() → dynamic
+static method bar3b<X extends self::A<self::A<self::A<core::int>>>>() → dynamic
   return throw 42;
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks.dart.weak.outline.expect b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks.dart.weak.outline.expect
index e66dde1..224c9fc 100644
--- a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks.dart.weak.outline.expect
@@ -156,24 +156,24 @@
   synthetic constructor •() → self::A<self::A::T%>
     ;
 }
-class Bar1<X extends self::A<self::A<core::int>> = self::A<self::A<core::int>>> extends core::Object {
+class Bar1<X extends self::A<self::A<core::int>>> extends core::Object {
   synthetic constructor •() → self::Bar1<self::Bar1::X>
     ;
   method barBar11() → self::A<self::A<core::int>>
     ;
   method barBar12(self::A<self::A<core::int>> x) → dynamic
     ;
-  method barBar13<X extends self::A<self::A<core::int>> = self::A<self::A<core::int>>>() → dynamic
+  method barBar13<X extends self::A<self::A<core::int>>>() → dynamic
     ;
 }
-class Bar2<X extends self::A<self::A<self::A<core::int>>> = self::A<self::A<self::A<core::int>>>> extends core::Object {
+class Bar2<X extends self::A<self::A<self::A<core::int>>>> extends core::Object {
   synthetic constructor •() → self::Bar2<self::Bar2::X>
     ;
   method barBar21() → self::A<self::A<self::A<core::int>>>
     ;
   method barBar22(self::A<self::A<self::A<core::int>>> x) → dynamic
     ;
-  method barBar23<X extends self::A<self::A<self::A<core::int>>> = self::A<self::A<self::A<core::int>>>>() → dynamic
+  method barBar23<X extends self::A<self::A<self::A<core::int>>>>() → dynamic
     ;
 }
 static method foo() → dynamic
@@ -186,9 +186,9 @@
   ;
 static method bar2b(self::A<self::A<self::A<core::int>>> x) → dynamic
   ;
-static method bar3a<X extends self::A<self::A<core::int>> = self::A<self::A<core::int>>>() → dynamic
+static method bar3a<X extends self::A<self::A<core::int>>>() → dynamic
   ;
-static method bar3b<X extends self::A<self::A<self::A<core::int>>> = self::A<self::A<self::A<core::int>>>>() → dynamic
+static method bar3b<X extends self::A<self::A<self::A<core::int>>>>() → dynamic
   ;
 static method main() → dynamic
   ;
diff --git a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks.dart.weak.transformed.expect b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks.dart.weak.transformed.expect
index 7506643..68d1353 100644
--- a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks.dart.weak.transformed.expect
@@ -175,7 +175,7 @@
     : super core::Object::•()
     ;
 }
-class Bar1<X extends self::A<self::A<core::int>> = self::A<self::A<core::int>>> extends core::Object {
+class Bar1<X extends self::A<self::A<core::int>>> extends core::Object {
   synthetic constructor •() → self::Bar1<self::Bar1::X>
     : super core::Object::•()
     ;
@@ -183,10 +183,10 @@
     return throw 42;
   method barBar12(self::A<self::A<core::int>> x) → dynamic
     return throw 42;
-  method barBar13<X extends self::A<self::A<core::int>> = self::A<self::A<core::int>>>() → dynamic
+  method barBar13<X extends self::A<self::A<core::int>>>() → dynamic
     return throw 42;
 }
-class Bar2<X extends self::A<self::A<self::A<core::int>>> = self::A<self::A<self::A<core::int>>>> extends core::Object {
+class Bar2<X extends self::A<self::A<self::A<core::int>>>> extends core::Object {
   synthetic constructor •() → self::Bar2<self::Bar2::X>
     : super core::Object::•()
     ;
@@ -194,7 +194,7 @@
     return throw 42;
   method barBar22(self::A<self::A<self::A<core::int>>> x) → dynamic
     return throw 42;
-  method barBar23<X extends self::A<self::A<self::A<core::int>>> = self::A<self::A<self::A<core::int>>>>() → dynamic
+  method barBar23<X extends self::A<self::A<self::A<core::int>>>>() → dynamic
     return throw 42;
 }
 static method foo() → dynamic {
@@ -209,8 +209,8 @@
   return throw 42;
 static method bar2b(self::A<self::A<self::A<core::int>>> x) → dynamic
   return throw 42;
-static method bar3a<X extends self::A<self::A<core::int>> = self::A<self::A<core::int>>>() → dynamic
+static method bar3a<X extends self::A<self::A<core::int>>>() → dynamic
   return throw 42;
-static method bar3b<X extends self::A<self::A<self::A<core::int>>> = self::A<self::A<self::A<core::int>>>>() → dynamic
+static method bar3b<X extends self::A<self::A<self::A<core::int>>>>() → dynamic
   return throw 42;
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_in_typedef.dart.strong.expect b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_in_typedef.dart.strong.expect
index 2b7816b..221969e 100644
--- a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_in_typedef.dart.strong.expect
+++ b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_in_typedef.dart.strong.expect
@@ -29,9 +29,9 @@
 import self as self;
 import "dart:core" as core;
 
-typedef A<unrelated X extends core::int = core::int> = core::String;
-typedef B<unrelated X extends core::int = core::int> = core::String;
-typedef C<X extends core::int = core::int> = X;
+typedef A<unrelated X extends core::int> = core::String;
+typedef B<unrelated X extends core::int> = core::String;
+typedef C<X extends core::int> = X;
 static method foo() → dynamic {
   core::String a;
 }
diff --git a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_in_typedef.dart.strong.transformed.expect b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_in_typedef.dart.strong.transformed.expect
index 2b7816b..221969e 100644
--- a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_in_typedef.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_in_typedef.dart.strong.transformed.expect
@@ -29,9 +29,9 @@
 import self as self;
 import "dart:core" as core;
 
-typedef A<unrelated X extends core::int = core::int> = core::String;
-typedef B<unrelated X extends core::int = core::int> = core::String;
-typedef C<X extends core::int = core::int> = X;
+typedef A<unrelated X extends core::int> = core::String;
+typedef B<unrelated X extends core::int> = core::String;
+typedef C<X extends core::int> = X;
 static method foo() → dynamic {
   core::String a;
 }
diff --git a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_in_typedef.dart.weak.expect b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_in_typedef.dart.weak.expect
index 2b7816b..221969e 100644
--- a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_in_typedef.dart.weak.expect
+++ b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_in_typedef.dart.weak.expect
@@ -29,9 +29,9 @@
 import self as self;
 import "dart:core" as core;
 
-typedef A<unrelated X extends core::int = core::int> = core::String;
-typedef B<unrelated X extends core::int = core::int> = core::String;
-typedef C<X extends core::int = core::int> = X;
+typedef A<unrelated X extends core::int> = core::String;
+typedef B<unrelated X extends core::int> = core::String;
+typedef C<X extends core::int> = X;
 static method foo() → dynamic {
   core::String a;
 }
diff --git a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_in_typedef.dart.weak.outline.expect b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_in_typedef.dart.weak.outline.expect
index 0649b07..9b82c3d 100644
--- a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_in_typedef.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_in_typedef.dart.weak.outline.expect
@@ -21,9 +21,9 @@
 import self as self;
 import "dart:core" as core;
 
-typedef A<unrelated X extends core::int = core::int> = core::String;
-typedef B<unrelated X extends core::int = core::int> = core::String;
-typedef C<X extends core::int = core::int> = X;
+typedef A<unrelated X extends core::int> = core::String;
+typedef B<unrelated X extends core::int> = core::String;
+typedef C<X extends core::int> = X;
 static method foo() → dynamic
   ;
 static method main() → dynamic
diff --git a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_in_typedef.dart.weak.transformed.expect b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_in_typedef.dart.weak.transformed.expect
index 2b7816b..221969e 100644
--- a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_in_typedef.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_in_typedef.dart.weak.transformed.expect
@@ -29,9 +29,9 @@
 import self as self;
 import "dart:core" as core;
 
-typedef A<unrelated X extends core::int = core::int> = core::String;
-typedef B<unrelated X extends core::int = core::int> = core::String;
-typedef C<X extends core::int = core::int> = X;
+typedef A<unrelated X extends core::int> = core::String;
+typedef B<unrelated X extends core::int> = core::String;
+typedef C<X extends core::int> = X;
 static method foo() → dynamic {
   core::String a;
 }
diff --git a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_no_bodies_main.dart.strong.expect b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_no_bodies_main.dart.strong.expect
index 381925d..2da2661 100644
--- a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_no_bodies_main.dart.strong.expect
+++ b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_no_bodies_main.dart.strong.expect
@@ -20,13 +20,13 @@
 import self as self2;
 import "dart:core" as core;
 
-typedef B<unrelated X extends core::String = core::String> = self2::A;
+typedef B<unrelated X extends core::String> = self2::A;
 class A extends core::Object {
   synthetic constructor •() → self2::A
     : super core::Object::•()
     ;
 }
-class C<Y extends self2::A = self2::A> extends core::Object {
+class C<Y extends self2::A> extends core::Object {
   synthetic constructor •() → self2::C<self2::C::Y>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_no_bodies_main.dart.strong.transformed.expect b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_no_bodies_main.dart.strong.transformed.expect
index 381925d..2da2661 100644
--- a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_no_bodies_main.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_no_bodies_main.dart.strong.transformed.expect
@@ -20,13 +20,13 @@
 import self as self2;
 import "dart:core" as core;
 
-typedef B<unrelated X extends core::String = core::String> = self2::A;
+typedef B<unrelated X extends core::String> = self2::A;
 class A extends core::Object {
   synthetic constructor •() → self2::A
     : super core::Object::•()
     ;
 }
-class C<Y extends self2::A = self2::A> extends core::Object {
+class C<Y extends self2::A> extends core::Object {
   synthetic constructor •() → self2::C<self2::C::Y>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_no_bodies_main.dart.weak.expect b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_no_bodies_main.dart.weak.expect
index 381925d..2da2661 100644
--- a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_no_bodies_main.dart.weak.expect
+++ b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_no_bodies_main.dart.weak.expect
@@ -20,13 +20,13 @@
 import self as self2;
 import "dart:core" as core;
 
-typedef B<unrelated X extends core::String = core::String> = self2::A;
+typedef B<unrelated X extends core::String> = self2::A;
 class A extends core::Object {
   synthetic constructor •() → self2::A
     : super core::Object::•()
     ;
 }
-class C<Y extends self2::A = self2::A> extends core::Object {
+class C<Y extends self2::A> extends core::Object {
   synthetic constructor •() → self2::C<self2::C::Y>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_no_bodies_main.dart.weak.outline.expect b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_no_bodies_main.dart.weak.outline.expect
index ecbd101..9cbea69 100644
--- a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_no_bodies_main.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_no_bodies_main.dart.weak.outline.expect
@@ -21,12 +21,12 @@
 import self as self2;
 import "dart:core" as core;
 
-typedef B<unrelated X extends core::String = core::String> = self2::A;
+typedef B<unrelated X extends core::String> = self2::A;
 class A extends core::Object {
   synthetic constructor •() → self2::A
     ;
 }
-class C<Y extends self2::A = self2::A> extends core::Object {
+class C<Y extends self2::A> extends core::Object {
   synthetic constructor •() → self2::C<self2::C::Y>
     ;
 }
diff --git a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_no_bodies_main.dart.weak.transformed.expect b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_no_bodies_main.dart.weak.transformed.expect
index 381925d..2da2661 100644
--- a/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_no_bodies_main.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nonfunction_type_aliases/aliased_checks_no_bodies_main.dart.weak.transformed.expect
@@ -20,13 +20,13 @@
 import self as self2;
 import "dart:core" as core;
 
-typedef B<unrelated X extends core::String = core::String> = self2::A;
+typedef B<unrelated X extends core::String> = self2::A;
 class A extends core::Object {
   synthetic constructor •() → self2::A
     : super core::Object::•()
     ;
 }
-class C<Y extends self2::A = self2::A> extends core::Object {
+class C<Y extends self2::A> extends core::Object {
   synthetic constructor •() → self2::C<self2::C::Y>
     : super core::Object::•()
     ;
diff --git a/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls.dart.strong.expect b/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls.dart.strong.expect
index 0c361f8..d805d8c 100644
--- a/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls.dart.strong.expect
+++ b/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls.dart.strong.expect
@@ -13,7 +13,7 @@
 import self as self;
 import "dart:core" as core;
 
-typedef A<X extends core::num = core::num, unrelated Y extends core::Object? = dynamic> = self::C<X>;
+typedef A<X extends core::num, unrelated Y extends core::Object? = dynamic> = self::C<X>;
 class C<X extends core::Object? = dynamic> extends core::Object {
   synthetic constructor •() → self::C<self::C::X%>
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls.dart.strong.transformed.expect b/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls.dart.strong.transformed.expect
index 0c361f8..d805d8c 100644
--- a/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls.dart.strong.transformed.expect
@@ -13,7 +13,7 @@
 import self as self;
 import "dart:core" as core;
 
-typedef A<X extends core::num = core::num, unrelated Y extends core::Object? = dynamic> = self::C<X>;
+typedef A<X extends core::num, unrelated Y extends core::Object? = dynamic> = self::C<X>;
 class C<X extends core::Object? = dynamic> extends core::Object {
   synthetic constructor •() → self::C<self::C::X%>
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls.dart.weak.expect b/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls.dart.weak.expect
index 0c361f8..d805d8c 100644
--- a/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls.dart.weak.expect
+++ b/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls.dart.weak.expect
@@ -13,7 +13,7 @@
 import self as self;
 import "dart:core" as core;
 
-typedef A<X extends core::num = core::num, unrelated Y extends core::Object? = dynamic> = self::C<X>;
+typedef A<X extends core::num, unrelated Y extends core::Object? = dynamic> = self::C<X>;
 class C<X extends core::Object? = dynamic> extends core::Object {
   synthetic constructor •() → self::C<self::C::X%>
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls.dart.weak.outline.expect b/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls.dart.weak.outline.expect
index 67117f8..0b4358a 100644
--- a/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls.dart.weak.outline.expect
@@ -2,7 +2,7 @@
 import self as self;
 import "dart:core" as core;
 
-typedef A<X extends core::num = core::num, unrelated Y extends core::Object? = dynamic> = self::C<X>;
+typedef A<X extends core::num, unrelated Y extends core::Object? = dynamic> = self::C<X>;
 class C<X extends core::Object? = dynamic> extends core::Object {
   synthetic constructor •() → self::C<self::C::X%>
     ;
diff --git a/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls.dart.weak.transformed.expect b/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls.dart.weak.transformed.expect
index 0c361f8..d805d8c 100644
--- a/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls.dart.weak.transformed.expect
@@ -13,7 +13,7 @@
 import self as self;
 import "dart:core" as core;
 
-typedef A<X extends core::num = core::num, unrelated Y extends core::Object? = dynamic> = self::C<X>;
+typedef A<X extends core::num, unrelated Y extends core::Object? = dynamic> = self::C<X>;
 class C<X extends core::Object? = dynamic> extends core::Object {
   synthetic constructor •() → self::C<self::C::X%>
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls_with_parts_main.dart.strong.expect b/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls_with_parts_main.dart.strong.expect
index afdc55d..98796c8 100644
--- a/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls_with_parts_main.dart.strong.expect
+++ b/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls_with_parts_main.dart.strong.expect
@@ -21,7 +21,7 @@
 import "dart:core" as core;
 
 part ./unaliased_bounds_checks_in_constructor_calls_with_parts_part_lib.dart;
-typedef A<X extends core::num = core::num, unrelated Y extends core::Object? = dynamic> = self2::C<X>;
+typedef A<X extends core::num, unrelated Y extends core::Object? = dynamic> = self2::C<X>;
 class C<X extends core::Object? = dynamic> extends core::Object { // from org-dartlang-testcase:///unaliased_bounds_checks_in_constructor_calls_with_parts_part_lib.dart
   synthetic constructor •() → self2::C<self2::C::X%>
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls_with_parts_main.dart.strong.transformed.expect b/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls_with_parts_main.dart.strong.transformed.expect
index afdc55d..98796c8 100644
--- a/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls_with_parts_main.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls_with_parts_main.dart.strong.transformed.expect
@@ -21,7 +21,7 @@
 import "dart:core" as core;
 
 part ./unaliased_bounds_checks_in_constructor_calls_with_parts_part_lib.dart;
-typedef A<X extends core::num = core::num, unrelated Y extends core::Object? = dynamic> = self2::C<X>;
+typedef A<X extends core::num, unrelated Y extends core::Object? = dynamic> = self2::C<X>;
 class C<X extends core::Object? = dynamic> extends core::Object { // from org-dartlang-testcase:///unaliased_bounds_checks_in_constructor_calls_with_parts_part_lib.dart
   synthetic constructor •() → self2::C<self2::C::X%>
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls_with_parts_main.dart.weak.expect b/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls_with_parts_main.dart.weak.expect
index afdc55d..98796c8 100644
--- a/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls_with_parts_main.dart.weak.expect
+++ b/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls_with_parts_main.dart.weak.expect
@@ -21,7 +21,7 @@
 import "dart:core" as core;
 
 part ./unaliased_bounds_checks_in_constructor_calls_with_parts_part_lib.dart;
-typedef A<X extends core::num = core::num, unrelated Y extends core::Object? = dynamic> = self2::C<X>;
+typedef A<X extends core::num, unrelated Y extends core::Object? = dynamic> = self2::C<X>;
 class C<X extends core::Object? = dynamic> extends core::Object { // from org-dartlang-testcase:///unaliased_bounds_checks_in_constructor_calls_with_parts_part_lib.dart
   synthetic constructor •() → self2::C<self2::C::X%>
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls_with_parts_main.dart.weak.outline.expect b/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls_with_parts_main.dart.weak.outline.expect
index d3cc16c..ca7c9c2 100644
--- a/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls_with_parts_main.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls_with_parts_main.dart.weak.outline.expect
@@ -11,7 +11,7 @@
 import "dart:core" as core;
 
 part ./unaliased_bounds_checks_in_constructor_calls_with_parts_part_lib.dart;
-typedef A<X extends core::num = core::num, unrelated Y extends core::Object? = dynamic> = self2::C<X>;
+typedef A<X extends core::num, unrelated Y extends core::Object? = dynamic> = self2::C<X>;
 class C<X extends core::Object? = dynamic> extends core::Object { // from org-dartlang-testcase:///unaliased_bounds_checks_in_constructor_calls_with_parts_part_lib.dart
   synthetic constructor •() → self2::C<self2::C::X%>
     ;
diff --git a/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls_with_parts_main.dart.weak.transformed.expect b/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls_with_parts_main.dart.weak.transformed.expect
index afdc55d..98796c8 100644
--- a/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls_with_parts_main.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nonfunction_type_aliases/unaliased_bounds_checks_in_constructor_calls_with_parts_main.dart.weak.transformed.expect
@@ -21,7 +21,7 @@
 import "dart:core" as core;
 
 part ./unaliased_bounds_checks_in_constructor_calls_with_parts_part_lib.dart;
-typedef A<X extends core::num = core::num, unrelated Y extends core::Object? = dynamic> = self2::C<X>;
+typedef A<X extends core::num, unrelated Y extends core::Object? = dynamic> = self2::C<X>;
 class C<X extends core::Object? = dynamic> extends core::Object { // from org-dartlang-testcase:///unaliased_bounds_checks_in_constructor_calls_with_parts_part_lib.dart
   synthetic constructor •() → self2::C<self2::C::X%>
     : super core::Object::•()
diff --git a/pkg/front_end/testcases/regress/issue_31766.dart.weak.expect b/pkg/front_end/testcases/regress/issue_31766.dart.weak.expect
index 84f19bf..9fcb7e6 100644
--- a/pkg/front_end/testcases/regress/issue_31766.dart.weak.expect
+++ b/pkg/front_end/testcases/regress/issue_31766.dart.weak.expect
@@ -20,11 +20,11 @@
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
 static method main() → dynamic {
-  function bar<T extends self::A* = self::A*>(T* t) → void {
+  function bar<T extends self::A*>(T* t) → void {
     core::print("t.foo()=${t.{self::A::foo}()}");
   }
   bar.call<self::A*>(new self::A::•());
-  (<S extends self::A* = self::A*>(S* s) → Null {
+  (<S extends self::A*>(S* s) → Null {
     core::print("s.foo()=${s.{self::A::foo}()}");
   }).call<self::A*>(new self::A::•());
 }
diff --git a/pkg/front_end/testcases/regress/issue_31766.dart.weak.transformed.expect b/pkg/front_end/testcases/regress/issue_31766.dart.weak.transformed.expect
index 84f19bf..9fcb7e6 100644
--- a/pkg/front_end/testcases/regress/issue_31766.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/regress/issue_31766.dart.weak.transformed.expect
@@ -20,11 +20,11 @@
   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
 }
 static method main() → dynamic {
-  function bar<T extends self::A* = self::A*>(T* t) → void {
+  function bar<T extends self::A*>(T* t) → void {
     core::print("t.foo()=${t.{self::A::foo}()}");
   }
   bar.call<self::A*>(new self::A::•());
-  (<S extends self::A* = self::A*>(S* s) → Null {
+  (<S extends self::A*>(S* s) → Null {
     core::print("s.foo()=${s.{self::A::foo}()}");
   }).call<self::A*>(new self::A::•());
 }
diff --git a/pkg/front_end/testcases/regress/issue_31846.dart.weak.expect b/pkg/front_end/testcases/regress/issue_31846.dart.weak.expect
index 46e374c..98bf326 100644
--- a/pkg/front_end/testcases/regress/issue_31846.dart.weak.expect
+++ b/pkg/front_end/testcases/regress/issue_31846.dart.weak.expect
@@ -5,7 +5,7 @@
 static method main() → dynamic {
   core::print((#C1) is () →* dynamic);
   core::print((<T extends core::Object* = dynamic>(T* x) → T* => x).{core::Object::runtimeType});
-  core::print((<T extends core::num* = core::num*>(T* x) → T* => x).{core::Object::runtimeType});
+  core::print((<T extends core::num*>(T* x) → T* => x).{core::Object::runtimeType});
   core::print((<T extends core::Comparable<T*>* = core::Comparable<dynamic>*>(T* x) → T* => x).{core::Object::runtimeType});
   core::print((<T extends core::Comparable<S*>* = core::Comparable<dynamic>*, S extends core::Object* = dynamic>(T* x) → T* => x).{core::Object::runtimeType});
   core::print((<T extends (T*) →* dynamic = (Null) →* dynamic>(T* x) → T* => x).{core::Object::runtimeType});
diff --git a/pkg/front_end/testcases/regress/issue_31846.dart.weak.transformed.expect b/pkg/front_end/testcases/regress/issue_31846.dart.weak.transformed.expect
index 27bf019..4202e10 100644
--- a/pkg/front_end/testcases/regress/issue_31846.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/regress/issue_31846.dart.weak.transformed.expect
@@ -5,7 +5,7 @@
 static method main() → dynamic {
   core::print((#C1) is () →* dynamic);
   core::print((<T extends core::Object* = dynamic>(T* x) → T* => x).{core::Object::runtimeType});
-  core::print((<T extends core::num* = core::num*>(T* x) → T* => x).{core::Object::runtimeType});
+  core::print((<T extends core::num*>(T* x) → T* => x).{core::Object::runtimeType});
   core::print((<T extends core::Comparable<T*>* = core::Comparable<dynamic>*>(T* x) → T* => x).{core::Object::runtimeType});
   core::print((<T extends core::Comparable<S*>* = core::Comparable<dynamic>*, S extends core::Object* = dynamic>(T* x) → T* => x).{core::Object::runtimeType});
   core::print((<T extends (T*) →* dynamic = (Null) →* dynamic>(T* x) → T* => x).{core::Object::runtimeType});
diff --git a/pkg/front_end/testcases/runtime_checks/contravariant_generic_method_type_parameter.dart.weak.expect b/pkg/front_end/testcases/runtime_checks/contravariant_generic_method_type_parameter.dart.weak.expect
index 86eda63..d05b36d 100644
--- a/pkg/front_end/testcases/runtime_checks/contravariant_generic_method_type_parameter.dart.weak.expect
+++ b/pkg/front_end/testcases/runtime_checks/contravariant_generic_method_type_parameter.dart.weak.expect
@@ -7,7 +7,7 @@
   synthetic constructor •() → self::C<self::C::T*>*
     : super core::Object::•()
     ;
-  method f<U extends (self::C::T*) →* void = (self::C::T*) →* void>(self::C::f::U* x) → void {}
+  method f<U extends (self::C::T*) →* void>(self::C::f::U* x) → void {}
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
diff --git a/pkg/front_end/testcases/runtime_checks/contravariant_generic_method_type_parameter.dart.weak.outline.expect b/pkg/front_end/testcases/runtime_checks/contravariant_generic_method_type_parameter.dart.weak.outline.expect
index d92d1dd..713c4b7 100644
--- a/pkg/front_end/testcases/runtime_checks/contravariant_generic_method_type_parameter.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/runtime_checks/contravariant_generic_method_type_parameter.dart.weak.outline.expect
@@ -6,7 +6,7 @@
 class C<T extends core::Object* = dynamic> extends core::Object {
   synthetic constructor •() → self::C<self::C::T*>*
     ;
-  method f<U extends (self::C::T*) →* void = (self::C::T*) →* void>(self::C::f::U* x) → void
+  method f<U extends (self::C::T*) →* void>(self::C::f::U* x) → void
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
diff --git a/pkg/front_end/testcases/runtime_checks/contravariant_generic_method_type_parameter.dart.weak.transformed.expect b/pkg/front_end/testcases/runtime_checks/contravariant_generic_method_type_parameter.dart.weak.transformed.expect
index 86eda63..d05b36d 100644
--- a/pkg/front_end/testcases/runtime_checks/contravariant_generic_method_type_parameter.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/runtime_checks/contravariant_generic_method_type_parameter.dart.weak.transformed.expect
@@ -7,7 +7,7 @@
   synthetic constructor •() → self::C<self::C::T*>*
     : super core::Object::•()
     ;
-  method f<U extends (self::C::T*) →* void = (self::C::T*) →* void>(self::C::f::U* x) → void {}
+  method f<U extends (self::C::T*) →* void>(self::C::f::U* x) → void {}
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
diff --git a/pkg/front_end/testcases/runtime_checks/covariant_generic_method_type_parameter.dart.weak.expect b/pkg/front_end/testcases/runtime_checks/covariant_generic_method_type_parameter.dart.weak.expect
index 415bac4..a1b22b2 100644
--- a/pkg/front_end/testcases/runtime_checks/covariant_generic_method_type_parameter.dart.weak.expect
+++ b/pkg/front_end/testcases/runtime_checks/covariant_generic_method_type_parameter.dart.weak.expect
@@ -19,8 +19,8 @@
   synthetic constructor •() → self::C<self::C::T*>*
     : super core::Object::•()
     ;
-  method f<generic-covariant-impl U extends self::C::T* = self::C::T*>(self::C::f::U* x) → void {}
-  method g1<generic-covariant-impl U extends self::C::T* = self::C::T*>() → void {
+  method f<generic-covariant-impl U extends self::C::T*>(self::C::f::U* x) → void {}
+  method g1<generic-covariant-impl U extends self::C::T*>() → void {
     this.{self::C::f}<self::C::g1::U*>(let final Never* #t1 = invalid-expression "pkg/front_end/testcases/runtime_checks/covariant_generic_method_type_parameter.dart:11:15: Error: The argument type 'double' can't be assigned to the parameter type 'U'.
     this.f<U>(1.5);
               ^" in 1.5 as{TypeError} Never);
diff --git a/pkg/front_end/testcases/runtime_checks/covariant_generic_method_type_parameter.dart.weak.outline.expect b/pkg/front_end/testcases/runtime_checks/covariant_generic_method_type_parameter.dart.weak.outline.expect
index 2cae248..133cc4d 100644
--- a/pkg/front_end/testcases/runtime_checks/covariant_generic_method_type_parameter.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/runtime_checks/covariant_generic_method_type_parameter.dart.weak.outline.expect
@@ -5,9 +5,9 @@
 class C<T extends core::Object* = dynamic> extends core::Object {
   synthetic constructor •() → self::C<self::C::T*>*
     ;
-  method f<generic-covariant-impl U extends self::C::T* = self::C::T*>(self::C::f::U* x) → void
+  method f<generic-covariant-impl U extends self::C::T*>(self::C::f::U* x) → void
     ;
-  method g1<generic-covariant-impl U extends self::C::T* = self::C::T*>() → void
+  method g1<generic-covariant-impl U extends self::C::T*>() → void
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
diff --git a/pkg/front_end/testcases/runtime_checks/covariant_generic_method_type_parameter.dart.weak.transformed.expect b/pkg/front_end/testcases/runtime_checks/covariant_generic_method_type_parameter.dart.weak.transformed.expect
index 415bac4..a1b22b2 100644
--- a/pkg/front_end/testcases/runtime_checks/covariant_generic_method_type_parameter.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/runtime_checks/covariant_generic_method_type_parameter.dart.weak.transformed.expect
@@ -19,8 +19,8 @@
   synthetic constructor •() → self::C<self::C::T*>*
     : super core::Object::•()
     ;
-  method f<generic-covariant-impl U extends self::C::T* = self::C::T*>(self::C::f::U* x) → void {}
-  method g1<generic-covariant-impl U extends self::C::T* = self::C::T*>() → void {
+  method f<generic-covariant-impl U extends self::C::T*>(self::C::f::U* x) → void {}
+  method g1<generic-covariant-impl U extends self::C::T*>() → void {
     this.{self::C::f}<self::C::g1::U*>(let final Never* #t1 = invalid-expression "pkg/front_end/testcases/runtime_checks/covariant_generic_method_type_parameter.dart:11:15: Error: The argument type 'double' can't be assigned to the parameter type 'U'.
     this.f<U>(1.5);
               ^" in 1.5 as{TypeError} Never);
diff --git a/pkg/front_end/testcases/runtime_checks/dynamic_invocation_generic.dart.weak.expect b/pkg/front_end/testcases/runtime_checks/dynamic_invocation_generic.dart.weak.expect
index e202795..07dcc99 100644
--- a/pkg/front_end/testcases/runtime_checks/dynamic_invocation_generic.dart.weak.expect
+++ b/pkg/front_end/testcases/runtime_checks/dynamic_invocation_generic.dart.weak.expect
@@ -6,7 +6,7 @@
   synthetic constructor •() → self::C<self::C::T*>*
     : super core::Object::•()
     ;
-  method f<generic-covariant-impl U extends self::C::T* = self::C::T*>(self::C::f::U* x) → void {}
+  method f<generic-covariant-impl U extends self::C::T*>(self::C::f::U* x) → void {}
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
diff --git a/pkg/front_end/testcases/runtime_checks/dynamic_invocation_generic.dart.weak.outline.expect b/pkg/front_end/testcases/runtime_checks/dynamic_invocation_generic.dart.weak.outline.expect
index 8f33693..d66d1485 100644
--- a/pkg/front_end/testcases/runtime_checks/dynamic_invocation_generic.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/runtime_checks/dynamic_invocation_generic.dart.weak.outline.expect
@@ -5,7 +5,7 @@
 class C<T extends core::Object* = dynamic> extends core::Object {
   synthetic constructor •() → self::C<self::C::T*>*
     ;
-  method f<generic-covariant-impl U extends self::C::T* = self::C::T*>(self::C::f::U* x) → void
+  method f<generic-covariant-impl U extends self::C::T*>(self::C::f::U* x) → void
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
diff --git a/pkg/front_end/testcases/runtime_checks/dynamic_invocation_generic.dart.weak.transformed.expect b/pkg/front_end/testcases/runtime_checks/dynamic_invocation_generic.dart.weak.transformed.expect
index e202795..07dcc99 100644
--- a/pkg/front_end/testcases/runtime_checks/dynamic_invocation_generic.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/runtime_checks/dynamic_invocation_generic.dart.weak.transformed.expect
@@ -6,7 +6,7 @@
   synthetic constructor •() → self::C<self::C::T*>*
     : super core::Object::•()
     ;
-  method f<generic-covariant-impl U extends self::C::T* = self::C::T*>(self::C::f::U* x) → void {}
+  method f<generic-covariant-impl U extends self::C::T*>(self::C::f::U* x) → void {}
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
diff --git a/pkg/front_end/testcases/runtime_checks_new/derived_class_typed.dart.weak.expect b/pkg/front_end/testcases/runtime_checks_new/derived_class_typed.dart.weak.expect
index 4a4821f..eb1c927 100644
--- a/pkg/front_end/testcases/runtime_checks_new/derived_class_typed.dart.weak.expect
+++ b/pkg/front_end/testcases/runtime_checks_new/derived_class_typed.dart.weak.expect
@@ -8,7 +8,7 @@
     ;
   method f(generic-covariant-impl self::B::T* x) → void {}
   method g({generic-covariant-impl self::B::T* x = #C1}) → void {}
-  method h<generic-covariant-impl U extends self::B::T* = self::B::T*>() → void {}
+  method h<generic-covariant-impl U extends self::B::T*>() → void {}
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
diff --git a/pkg/front_end/testcases/runtime_checks_new/derived_class_typed.dart.weak.outline.expect b/pkg/front_end/testcases/runtime_checks_new/derived_class_typed.dart.weak.outline.expect
index 822b58a..2ebc576 100644
--- a/pkg/front_end/testcases/runtime_checks_new/derived_class_typed.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/runtime_checks_new/derived_class_typed.dart.weak.outline.expect
@@ -9,7 +9,7 @@
     ;
   method g({generic-covariant-impl self::B::T* x}) → void
     ;
-  method h<generic-covariant-impl U extends self::B::T* = self::B::T*>() → void
+  method h<generic-covariant-impl U extends self::B::T*>() → void
     ;
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
diff --git a/pkg/front_end/testcases/runtime_checks_new/derived_class_typed.dart.weak.transformed.expect b/pkg/front_end/testcases/runtime_checks_new/derived_class_typed.dart.weak.transformed.expect
index 4a4821f..eb1c927 100644
--- a/pkg/front_end/testcases/runtime_checks_new/derived_class_typed.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/runtime_checks_new/derived_class_typed.dart.weak.transformed.expect
@@ -8,7 +8,7 @@
     ;
   method f(generic-covariant-impl self::B::T* x) → void {}
   method g({generic-covariant-impl self::B::T* x = #C1}) → void {}
-  method h<generic-covariant-impl U extends self::B::T* = self::B::T*>() → void {}
+  method h<generic-covariant-impl U extends self::B::T*>() → void {}
   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
diff --git a/pkg/kernel/binary.md b/pkg/kernel/binary.md
index 0e9346f..1e83f7d 100644
--- a/pkg/kernel/binary.md
+++ b/pkg/kernel/binary.md
@@ -147,7 +147,7 @@
 
 type ComponentFile {
   UInt32 magic = 0x90ABCDEF;
-  UInt32 formatVersion = 62;
+  UInt32 formatVersion = 63;
   Byte[10] shortSdkHash;
   List<String> problemsAsJson; // Described in problems.md.
   Library[] libraries;
@@ -1496,7 +1496,7 @@
   Byte variance; // Index into the Variance enum above
   StringReference name; // Cosmetic, may be empty, not unique.
   DartType bound; // 'dynamic' if no explicit bound was given.
-  Option<DartType> defaultType; // type used when the parameter is not passed
+  DartType defaultType; // type used when the parameter is not passed
 }
 
 ```
diff --git a/pkg/kernel/lib/ast.dart b/pkg/kernel/lib/ast.dart
index 100535a..eb7f26f 100644
--- a/pkg/kernel/lib/ast.dart
+++ b/pkg/kernel/lib/ast.dart
@@ -5901,7 +5901,7 @@
               getterType.typeParameters,
               getterType.typeParameters
                   .map((TypeParameter typeParameter) =>
-                      typeParameter.defaultType!)
+                      typeParameter.defaultType)
                   .toList());
         }
         return substitution.substituteType(getterType.returnType);
@@ -11979,13 +11979,18 @@
   /// bound.
   DartType bound;
 
+  /// Sentinel value used for the [defaultType] that has not yet been computed.
+  /// This is needed to make the [defaultType] field non-nullable while
+  /// supporting recursive bounds for which the default type need to be set
+  /// late.
+  static final DartType unsetDefaultTypeSentinel = new InvalidType();
+
   /// The default value of the type variable. It is used to provide the
   /// corresponding missing type argument in type annotations and as the
   /// fall-back type value in type inference at compile time. At run time,
   /// [defaultType] is used by the backends in place of the missing type
   /// argument of a dynamic invocation of a generic function.
-  // TODO(johnniwinther): Can we make this late non-nullable?
-  DartType? defaultType;
+  DartType defaultType;
 
   /// Describes variance of the type parameter w.r.t. declaration on which it is
   /// defined. For classes, if variance is not explicitly set, the type
@@ -12003,8 +12008,9 @@
 
   static const int legacyCovariantSerializationMarker = 4;
 
-  TypeParameter([this.name, DartType? bound, this.defaultType])
-      : bound = bound ?? unsetBoundSentinel;
+  TypeParameter([this.name, DartType? bound, DartType? defaultType])
+      : bound = bound ?? unsetBoundSentinel,
+        defaultType = defaultType ?? unsetDefaultTypeSentinel;
 
   // Must match serialized bit positions.
   static const int FlagGenericCovariantImpl = 1 << 0;
@@ -12042,7 +12048,7 @@
   void visitChildren(Visitor v) {
     visitList(annotations, v);
     bound.accept(v);
-    defaultType?.accept(v);
+    defaultType.accept(v);
   }
 
   @override
@@ -12052,8 +12058,9 @@
     if (bound != null) {
       bound = v.visitDartType(bound);
     }
+    // ignore: unnecessary_null_comparison
     if (defaultType != null) {
-      defaultType = v.visitDartType(defaultType!);
+      defaultType = v.visitDartType(defaultType);
     }
   }
 
@@ -12064,13 +12071,9 @@
     if (bound != null) {
       bound = v.visitDartType(bound, cannotRemoveSentinel);
     }
+    // ignore: unnecessary_null_comparison
     if (defaultType != null) {
-      DartType newDefaultType = v.visitDartType(defaultType!, dummyDartType);
-      if (identical(newDefaultType, dummyDartType)) {
-        defaultType = null;
-      } else {
-        defaultType = newDefaultType;
-      }
+      defaultType = v.visitDartType(defaultType, cannotRemoveSentinel);
     }
   }
 
diff --git a/pkg/kernel/lib/binary/ast_from_binary.dart b/pkg/kernel/lib/binary/ast_from_binary.dart
index 7ed437e..a825278 100644
--- a/pkg/kernel/lib/binary/ast_from_binary.dart
+++ b/pkg/kernel/lib/binary/ast_from_binary.dart
@@ -3001,7 +3001,7 @@
     }
     node.name = readStringOrNullIfEmpty();
     node.bound = readDartType();
-    node.defaultType = readDartTypeOption();
+    node.defaultType = readDartType();
   }
 
   Arguments readArguments() {
diff --git a/pkg/kernel/lib/binary/ast_to_binary.dart b/pkg/kernel/lib/binary/ast_to_binary.dart
index 6e4052a..c2c35282 100644
--- a/pkg/kernel/lib/binary/ast_to_binary.dart
+++ b/pkg/kernel/lib/binary/ast_to_binary.dart
@@ -2401,8 +2401,7 @@
     }
     writeStringReference(node.name ?? '');
     writeNode(node.bound);
-    // TODO(johnniwinther): Make this non-optional.
-    writeOptionalNode(node.defaultType);
+    writeNode(node.defaultType);
   }
 
   @override
diff --git a/pkg/kernel/lib/binary/tag.dart b/pkg/kernel/lib/binary/tag.dart
index 752f84b..8fe71ec 100644
--- a/pkg/kernel/lib/binary/tag.dart
+++ b/pkg/kernel/lib/binary/tag.dart
@@ -174,7 +174,7 @@
   /// Internal version of kernel binary format.
   /// Bump it when making incompatible changes in kernel binaries.
   /// Keep in sync with runtime/vm/kernel_binary.h, pkg/kernel/binary.md.
-  static const int BinaryFormatVersion = 62;
+  static const int BinaryFormatVersion = 63;
 }
 
 abstract class ConstantTag {
diff --git a/pkg/kernel/lib/clone.dart b/pkg/kernel/lib/clone.dart
index 29a21e3..62b04d9 100644
--- a/pkg/kernel/lib/clone.dart
+++ b/pkg/kernel/lib/clone.dart
@@ -510,8 +510,9 @@
   visitTypeParameter(TypeParameter node) {
     TypeParameter newNode = typeParams[node]!;
     newNode.bound = visitType(node.bound);
+    // ignore: unnecessary_null_comparison
     if (node.defaultType != null) {
-      newNode.defaultType = visitType(node.defaultType!);
+      newNode.defaultType = visitType(node.defaultType);
     }
     return newNode
       ..annotations = cloneAnnotations && !node.annotations.isEmpty
diff --git a/pkg/kernel/lib/src/bounds_checks.dart b/pkg/kernel/lib/src/bounds_checks.dart
index 47b03e6..d1cdd54 100644
--- a/pkg/kernel/lib/src/bounds_checks.dart
+++ b/pkg/kernel/lib/src/bounds_checks.dart
@@ -88,7 +88,7 @@
   void visitFunctionType(FunctionType node) {
     for (TypeParameter typeParameter in node.typeParameters) {
       typeParameter.bound.accept(this);
-      typeParameter.defaultType?.accept(this);
+      typeParameter.defaultType.accept(this);
     }
     for (DartType parameter in node.positionalParameters) {
       parameter.accept(this);
@@ -171,7 +171,7 @@
           ? const NeverType.nonNullable()
           : const DynamicType();
     } else if (bound is InterfaceType && bound.classNode == objectClass) {
-      DartType defaultType = typeParameters[i].defaultType!;
+      DartType defaultType = typeParameters[i].defaultType;
       if (!(defaultType is InterfaceType &&
           defaultType.classNode == objectClass)) {
         bound = isNonNullableByDefault && isContravariant
diff --git a/pkg/kernel/lib/src/merge_visitor.dart b/pkg/kernel/lib/src/merge_visitor.dart
index d18083c..fe27f5c 100644
--- a/pkg/kernel/lib/src/merge_visitor.dart
+++ b/pkg/kernel/lib/src/merge_visitor.dart
@@ -81,7 +81,7 @@
         }
         newTypeParameters[i].bound = newBound;
         DartType? newDefaultType = mergeTypes(
-            a.typeParameters[i].defaultType!, b.typeParameters[i].defaultType!);
+            a.typeParameters[i].defaultType, b.typeParameters[i].defaultType);
         if (newDefaultType == null) {
           return null;
         }
diff --git a/pkg/kernel/lib/src/printer.dart b/pkg/kernel/lib/src/printer.dart
index cb4b9e6..b184440 100644
--- a/pkg/kernel/lib/src/printer.dart
+++ b/pkg/kernel/lib/src/printer.dart
@@ -274,7 +274,7 @@
           return false;
         }
 
-        if (!isTopObject(bound) || isTopObject(typeParameter.defaultType!)) {
+        if (!isTopObject(bound) || isTopObject(typeParameter.defaultType)) {
           // Include explicit bounds only.
           _sb.write(' extends ');
           writeType(bound);
diff --git a/pkg/kernel/lib/src/replacement_visitor.dart b/pkg/kernel/lib/src/replacement_visitor.dart
index ced29bc..b37a704 100644
--- a/pkg/kernel/lib/src/replacement_visitor.dart
+++ b/pkg/kernel/lib/src/replacement_visitor.dart
@@ -26,7 +26,7 @@
       DartType? newBound = typeParameter.bound
           .accept1(this, Variance.combine(variance, Variance.invariant));
       DartType? newDefaultType = typeParameter.defaultType
-          ?.accept1(this, Variance.combine(variance, Variance.invariant));
+          .accept1(this, Variance.combine(variance, Variance.invariant));
       if (newBound != null || newDefaultType != null) {
         newTypeParameters ??= node.typeParameters.toList(growable: false);
         newTypeParameters[i] = new TypeParameter(
diff --git a/pkg/kernel/lib/text/ast_to_text.dart b/pkg/kernel/lib/text/ast_to_text.dart
index 84484e7..5066b0a 100644
--- a/pkg/kernel/lib/text/ast_to_text.dart
+++ b/pkg/kernel/lib/text/ast_to_text.dart
@@ -2516,9 +2516,10 @@
     writeWord(getTypeParameterName(node));
     writeSpaced('extends');
     writeType(node.bound);
-    if (node.defaultType != null) {
+    // ignore: unnecessary_null_comparison
+    if (node.defaultType != node.bound) {
       writeSpaced('=');
-      writeType(node.defaultType!);
+      writeType(node.defaultType);
     }
   }
 
diff --git a/pkg/kernel/lib/text/text_serializer.dart b/pkg/kernel/lib/text/text_serializer.dart
index 82aaee6..ac705f2 100644
--- a/pkg/kernel/lib/text/text_serializer.dart
+++ b/pkg/kernel/lib/text/text_serializer.dart
@@ -1195,20 +1195,20 @@
     zipTypeParameterDefaultType,
     unzipTypeParameterDefaultType);
 
-TypeParameter zipTypeParameterBound(TypeParameter node, DartType? bound) {
-  return node..bound = bound!;
+TypeParameter zipTypeParameterBound(TypeParameter node, DartType bound) {
+  return node..bound = bound;
 }
 
-Tuple2<TypeParameter, DartType?> unzipTypeParameterBound(TypeParameter node) {
+Tuple2<TypeParameter, DartType> unzipTypeParameterBound(TypeParameter node) {
   return new Tuple2(node, node.bound);
 }
 
 TypeParameter zipTypeParameterDefaultType(
-    TypeParameter node, DartType? defaultType) {
+    TypeParameter node, DartType defaultType) {
   return node..defaultType = defaultType;
 }
 
-Tuple2<TypeParameter, DartType?> unzipTypeParameterDefaultType(
+Tuple2<TypeParameter, DartType> unzipTypeParameterDefaultType(
     TypeParameter node) {
   return new Tuple2(node, node.defaultType);
 }
diff --git a/pkg/kernel/lib/type_algebra.dart b/pkg/kernel/lib/type_algebra.dart
index d40825c..c273494 100644
--- a/pkg/kernel/lib/type_algebra.dart
+++ b/pkg/kernel/lib/type_algebra.dart
@@ -121,9 +121,7 @@
     TypeParameter freshTypeParameter = freshParameters[i];
 
     freshTypeParameter.bound = substitute(typeParameter.bound, map);
-    freshTypeParameter.defaultType = typeParameter.defaultType != null
-        ? substitute(typeParameter.defaultType!, map)
-        : null;
+    freshTypeParameter.defaultType = substitute(typeParameter.defaultType, map);
     freshTypeParameter.variance =
         typeParameter.isLegacyCovariant ? null : typeParameter.variance;
     // Annotations on a type parameter are specific to the declaration of the
@@ -384,8 +382,9 @@
     TypeParameterType typeParameterType = substitution[node] =
         new TypeParameterType.forAlphaRenaming(node, fresh);
     fresh.bound = visit(node.bound);
+    // ignore: unnecessary_null_comparison
     if (node.defaultType != null) {
-      fresh.defaultType = visit(node.defaultType!);
+      fresh.defaultType = visit(node.defaultType);
     }
     // If the bound was changed from substituting the bound we need to update
     // implicit nullability to be based on the new bound. If the bound wasn't
@@ -701,8 +700,9 @@
   bool handleTypeParameter(TypeParameter node) {
     assert(!variables.contains(node));
     if (node.bound.accept(this)) return true;
+    // ignore: unnecessary_null_comparison
     if (node.defaultType == null) return false;
-    return node.defaultType!.accept(this);
+    return node.defaultType.accept(this);
   }
 }
 
@@ -760,8 +760,9 @@
   bool handleTypeParameter(TypeParameter node) {
     assert(variables.contains(node));
     if (node.bound.accept(this)) return true;
+    // ignore: unnecessary_null_comparison
     if (node.defaultType == null) return false;
-    return node.defaultType!.accept(this);
+    return node.defaultType.accept(this);
   }
 }
 
@@ -819,8 +820,9 @@
   bool handleTypeParameter(TypeParameter node) {
     assert(variables.contains(node));
     if (node.bound.accept(this)) return true;
+    // ignore: unnecessary_null_comparison
     if (node.defaultType == null) return false;
-    return node.defaultType!.accept(this);
+    return node.defaultType.accept(this);
   }
 }
 
diff --git a/pkg/kernel/lib/verifier.dart b/pkg/kernel/lib/verifier.dart
index 01e2f7d..ad79a99 100644
--- a/pkg/kernel/lib/verifier.dart
+++ b/pkg/kernel/lib/verifier.dart
@@ -186,7 +186,8 @@
         problem(
             currentParent, "Missing bound for type parameter '$parameter'.");
       }
-      if (parameter.defaultType == null) {
+      if (identical(
+          parameter.defaultType, TypeParameter.unsetDefaultTypeSentinel)) {
         problem(currentParent,
             "Missing default type for type parameter '$parameter'.");
       }
diff --git a/pkg/kernel/test/class_hierarchy_test.dart b/pkg/kernel/test/class_hierarchy_test.dart
index dc68f05..65b263d 100644
--- a/pkg/kernel/test/class_hierarchy_test.dart
+++ b/pkg/kernel/test/class_hierarchy_test.dart
@@ -338,7 +338,8 @@
       {Supertype extends_(List<DartType> typeParameterTypes),
       List<Supertype> implements_(List<DartType> typeParameterTypes)}) {
     var typeParameters = typeParameterNames
-        .map((name) => new TypeParameter(name, coreTypes.objectLegacyRawType))
+        .map((name) => new TypeParameter(
+            name, coreTypes.objectLegacyRawType, coreTypes.objectLegacyRawType))
         .toList();
     var typeParameterTypes = typeParameters
         .map(
@@ -581,7 +582,8 @@
 
     var a = addGenericClass('A', ['T', 'U']);
 
-    var bT = new TypeParameter('T', coreTypes.objectLegacyRawType);
+    var bT = new TypeParameter(
+        'T', coreTypes.objectLegacyRawType, coreTypes.objectLegacyRawType);
     var bTT = new TypeParameterType(bT, Nullability.legacy);
     var b = addClass(new Class(
         name: 'B',
@@ -613,7 +615,8 @@
 
     var a = addGenericClass('A', ['T', 'U']);
 
-    var bT = new TypeParameter('T', coreTypes.objectLegacyRawType);
+    var bT = new TypeParameter(
+        'T', coreTypes.objectLegacyRawType, coreTypes.objectLegacyRawType);
     var bTT = new TypeParameterType(bT, Nullability.legacy);
     var b = addClass(new Class(
         name: 'B',
@@ -651,7 +654,8 @@
 
     var a = addGenericClass('A', ['T', 'U']);
 
-    var bT = new TypeParameter('T', coreTypes.objectLegacyRawType);
+    var bT = new TypeParameter(
+        'T', coreTypes.objectLegacyRawType, coreTypes.objectLegacyRawType);
     var bTT = new TypeParameterType(bT, Nullability.legacy);
     var b = addClass(new Class(
         name: 'B',
@@ -1327,7 +1331,8 @@
 
     var a = addGenericClass('A', ['T', 'U']);
 
-    var bT = new TypeParameter('T', coreTypes.objectLegacyRawType);
+    var bT = new TypeParameter(
+        'T', coreTypes.objectLegacyRawType, coreTypes.objectLegacyRawType);
     var bTT = new TypeParameterType(bT, Nullability.legacy);
     var b = addClass(new Class(
         name: 'B',
diff --git a/runtime/vm/compiler/frontend/kernel_fingerprints.cc b/runtime/vm/compiler/frontend/kernel_fingerprints.cc
index aff6de7..5d5890f 100644
--- a/runtime/vm/compiler/frontend/kernel_fingerprints.cc
+++ b/runtime/vm/compiler/frontend/kernel_fingerprints.cc
@@ -169,10 +169,8 @@
 
   helper.ReadUntilExcluding(TypeParameterHelper::kBound);
   // The helper isn't needed after this point.
-  CalculateDartTypeFingerprint();
-  if (ReadTag() == kSomething) {
-    CalculateDartTypeFingerprint();
-  }
+  CalculateDartTypeFingerprint();  // read bound
+  CalculateDartTypeFingerprint();  // read default type
   BuildHash(helper.flags_);
 }
 
diff --git a/runtime/vm/compiler/frontend/kernel_translation_helper.cc b/runtime/vm/compiler/frontend/kernel_translation_helper.cc
index 4ede221..5808db3 100644
--- a/runtime/vm/compiler/frontend/kernel_translation_helper.cc
+++ b/runtime/vm/compiler/frontend/kernel_translation_helper.cc
@@ -927,9 +927,7 @@
         helper_->SkipDartType();
         break;
       case kDefaultType:
-        if (helper_->ReadTag() == kSomething) {
-          helper_->SkipDartType();
-        }
+        helper_->SkipDartType();
         break;
       case kEnd:
         return;
@@ -3393,11 +3391,8 @@
     AbstractType& bound = BuildTypeWithoutFinalization();  // read ith bound.
     parameter.set_bound(bound);
     helper.ReadUntilExcludingAndSetJustRead(TypeParameterHelper::kDefaultType);
-    const AbstractType* default_arg = &Object::dynamic_type();
-    if (helper_->ReadTag() == kSomething) {
-      default_arg = &BuildTypeWithoutFinalization();
-    }
-    parameter.set_default_argument(*default_arg);
+    AbstractType& default_arg = BuildTypeWithoutFinalization();
+    parameter.set_default_argument(default_arg);
     helper.Finish();
   }
 
diff --git a/runtime/vm/compiler/frontend/scope_builder.cc b/runtime/vm/compiler/frontend/scope_builder.cc
index e2be4a9..81730a0 100644
--- a/runtime/vm/compiler/frontend/scope_builder.cc
+++ b/runtime/vm/compiler/frontend/scope_builder.cc
@@ -538,9 +538,7 @@
     helper.ReadUntilExcludingAndSetJustRead(TypeParameterHelper::kBound);
     VisitDartType();  // read ith bound.
     helper.ReadUntilExcludingAndSetJustRead(TypeParameterHelper::kDefaultType);
-    if (helper_.ReadTag() == kSomething) {
-      VisitDartType();  // read ith default type.
-    }
+    VisitDartType();  // read ith default type.
     helper.Finish();
   }
   function_node_helper.SetJustRead(FunctionNodeHelper::kTypeParameters);
@@ -1357,9 +1355,7 @@
       VisitDartType();  // read bound.
       helper.ReadUntilExcludingAndSetJustRead(
           TypeParameterHelper::kDefaultType);
-      if (helper_.ReadTag() == kSomething) {
-        VisitDartType();  // read default type.
-      }
+      VisitDartType();  // read default type.
       helper.Finish();
     }
     helper_.ReadUInt();  // read required parameter count.
diff --git a/runtime/vm/kernel_binary.h b/runtime/vm/kernel_binary.h
index 6259fe8..38ca8fa 100644
--- a/runtime/vm/kernel_binary.h
+++ b/runtime/vm/kernel_binary.h
@@ -20,8 +20,8 @@
 static const uint32_t kMagicProgramFile = 0x90ABCDEFu;
 
 // Both version numbers are inclusive.
-static const uint32_t kMinSupportedKernelFormatVersion = 62;
-static const uint32_t kMaxSupportedKernelFormatVersion = 62;
+static const uint32_t kMinSupportedKernelFormatVersion = 63;
+static const uint32_t kMaxSupportedKernelFormatVersion = 63;
 
 // Keep in sync with package:kernel/lib/binary/tag.dart
 #define KERNEL_TAG_LIST(V)                                                     \