diff --git a/pkg/_fe_analyzer_shared/test/flow_analysis/nullability/data/local_boolean.dart b/pkg/_fe_analyzer_shared/test/flow_analysis/nullability/data/local_boolean.dart
index 4c7b408..7fd0b63 100644
--- a/pkg/_fe_analyzer_shared/test/flow_analysis/nullability/data/local_boolean.dart
+++ b/pkg/_fe_analyzer_shared/test/flow_analysis/nullability/data/local_boolean.dart
@@ -11,6 +11,16 @@
   }
 }
 
+finalLocalBool_untyped(int? x) {
+  final b = x == null;
+  if (!b) {
+    // No promotion due to https://github.com/dart-lang/language/issues/1785
+    x;
+  } else {
+    x;
+  }
+}
+
 localBool(int? x) {
   bool b = x == null;
   if (!b) {
@@ -20,6 +30,16 @@
   }
 }
 
+localBool_untyped(int? x) {
+  var b = x == null;
+  if (!b) {
+    // No promotion due to https://github.com/dart-lang/language/issues/1785
+    x;
+  } else {
+    x;
+  }
+}
+
 localBool_assigned(int? x, bool b1) {
   bool b2 = b1;
   b2 = x == null;
@@ -30,6 +50,16 @@
   }
 }
 
+localBool_assigned_untyped(int? x, bool b1) {
+  var b2 = b1;
+  b2 = x == null;
+  if (!b2) {
+    /*nonNullable*/ x;
+  } else {
+    x;
+  }
+}
+
 localBool_assignedDynamic(int? x, bool b1) {
   dynamic b2 = b1;
   b2 = x == null;
@@ -49,6 +79,15 @@
   }
 }
 
+parameter_assigned_untyped(int? x, b) {
+  b = x == null;
+  if (!b) {
+    /*nonNullable*/ x;
+  } else {
+    x;
+  }
+}
+
 parameter_assignedDynamic(int? x, dynamic b) {
   b = x == null;
   if (!b) {
@@ -69,6 +108,17 @@
   }
 }
 
+lateFinalLocalBool_untyped(int? x) {
+  late final b = x == null;
+  if (!b) {
+    // We don't promote based on the initializers of late locals because we
+    // don't know when they execute.
+    x;
+  } else {
+    x;
+  }
+}
+
 lateLocalBool(int? x) {
   late bool b = x == null;
   if (!b) {
@@ -80,6 +130,17 @@
   }
 }
 
+lateLocalBool_untyped(int? x) {
+  late var b = x == null;
+  if (!b) {
+    // We don't promote based on the initializers of late locals because we
+    // don't know when they execute.
+    x;
+  } else {
+    x;
+  }
+}
+
 lateLocalBool_assignedAndInitialized(int? x, bool b1) {
   late bool b2 = b1;
   b2 = x == null;
@@ -90,6 +151,16 @@
   }
 }
 
+lateLocalBool_assignedAndInitialized_untyped(int? x, bool b1) {
+  late var b2 = b1;
+  b2 = x == null;
+  if (!b2) {
+    /*nonNullable*/ x;
+  } else {
+    x;
+  }
+}
+
 lateLocalBool_assignedButNotInitialized(int? x) {
   late bool b;
   b = x == null;
@@ -100,6 +171,16 @@
   }
 }
 
+lateLocalBool_assignedButNotInitialized_untyped(int? x) {
+  late var b;
+  b = x == null;
+  if (!b) {
+    /*nonNullable*/ x;
+  } else {
+    x;
+  }
+}
+
 rebaseWithDemotion(int? x, int? y, int? z, int? a) {
   x;
   y;
diff --git a/pkg/_fe_analyzer_shared/test/flow_analysis/type_promotion/data/initialization.dart b/pkg/_fe_analyzer_shared/test/flow_analysis/type_promotion/data/initialization.dart
index 35f2d63..799b884 100644
--- a/pkg/_fe_analyzer_shared/test/flow_analysis/type_promotion/data/initialization.dart
+++ b/pkg/_fe_analyzer_shared/test/flow_analysis/type_promotion/data/initialization.dart
@@ -13,6 +13,11 @@
   x;
 }
 
+localVariable_null() {
+  var x = null;
+  x;
+}
+
 localVariable_hasInitializer(num a) {
   var x = a;
   x = 1;
diff --git a/pkg/analyzer/lib/src/generated/resolver.dart b/pkg/analyzer/lib/src/generated/resolver.dart
index 8acd4ac..2ef5319 100644
--- a/pkg/analyzer/lib/src/generated/resolver.dart
+++ b/pkg/analyzer/lib/src/generated/resolver.dart
@@ -282,13 +282,6 @@
   /// always safe to use `.last` to examine the top of the stack.
   final List<Expression?> _unfinishedNullShorts = [null];
 
-  /// During resolution we clone annotation ASTs into the element model.
-  /// But we should not do this during linking element models, moreover
-  /// currently by doing this we will lose elements for parameters of
-  /// generic function types.
-  /// TODO(scheglov) Stop cloning altogether.
-  bool shouldCloneAnnotations = true;
-
   late final FunctionReferenceResolver _functionReferenceResolver;
 
   late final InstanceCreationExpressionResolver
diff --git a/pkg/analyzer/lib/src/summary2/ast_resolver.dart b/pkg/analyzer/lib/src/summary2/ast_resolver.dart
index 3f7a44a..96f8760 100644
--- a/pkg/analyzer/lib/src/summary2/ast_resolver.dart
+++ b/pkg/analyzer/lib/src/summary2/ast_resolver.dart
@@ -55,7 +55,6 @@
       : _featureSet = node.thisOrAncestorOfType<CompilationUnit>()!.featureSet;
 
   void resolveAnnotation(AnnotationImpl node) {
-    _resolverVisitor.shouldCloneAnnotations = false;
     node.accept(_resolutionVisitor);
     node.accept(_scopeResolverVisitor);
     _prepareEnclosingDeclarations();
diff --git a/pkg/compiler/test/deferred_loading/data/instantiation2/main.dart b/pkg/compiler/test/deferred_loading/data/instantiation2/main.dart
index bf10d09..509c0ef 100644
--- a/pkg/compiler/test/deferred_loading/data/instantiation2/main.dart
+++ b/pkg/compiler/test/deferred_loading/data/instantiation2/main.dart
@@ -16,7 +16,19 @@
   c=(f3, f2)]
 */
 
-/*two-frag|three-frag.library: 
+/*two-frag.library: 
+ a_pre_fragments=[
+  p1: {units: [3{c}, 1{b}], usedBy: [p2], needs: []},
+  p2: {units: [2{b, c}], usedBy: [], needs: [p1]}],
+ b_finalized_fragments=[
+  f1: [3{c}, 1{b}],
+  f2: [2{b, c}]],
+ c_steps=[
+  b=(f2, f1),
+  c=(f2, f1)]
+*/
+
+/*three-frag.library: 
  a_pre_fragments=[
   p1: {units: [1{b}], usedBy: [p3], needs: []},
   p2: {units: [3{c}], usedBy: [p3], needs: []},
diff --git a/pkg/compiler/test/deferred_loading/data/instantiation5/main.dart b/pkg/compiler/test/deferred_loading/data/instantiation5/main.dart
index 0ba4442..2d808b3 100644
--- a/pkg/compiler/test/deferred_loading/data/instantiation5/main.dart
+++ b/pkg/compiler/test/deferred_loading/data/instantiation5/main.dart
@@ -16,7 +16,19 @@
   c=(f3, f2)]
 */
 
-/*two-frag|three-frag.library: 
+/*two-frag.library: 
+ a_pre_fragments=[
+  p1: {units: [3{c}, 1{b}], usedBy: [p2], needs: []},
+  p2: {units: [2{b, c}], usedBy: [], needs: [p1]}],
+ b_finalized_fragments=[
+  f1: [3{c}, 1{b}],
+  f2: [2{b, c}]],
+ c_steps=[
+  b=(f2, f1),
+  c=(f2, f1)]
+*/
+
+/*three-frag.library: 
  a_pre_fragments=[
   p1: {units: [1{b}], usedBy: [p3], needs: []},
   p2: {units: [3{c}], usedBy: [p3], needs: []},
diff --git a/sdk/lib/_internal/js_runtime/lib/instantiation.dart b/sdk/lib/_internal/js_runtime/lib/instantiation.dart
index da3fcbd..38c403d 100644
--- a/sdk/lib/_internal/js_runtime/lib/instantiation.dart
+++ b/sdk/lib/_internal/js_runtime/lib/instantiation.dart
@@ -22,6 +22,13 @@
     }
   }
 
+  bool operator ==(Object other) =>
+      other is Instantiation &&
+      this._genericClosure == other._genericClosure &&
+      this.runtimeType == other.runtimeType;
+
+  int get hashCode => Object.hash(_genericClosure, runtimeType);
+
   /// Returns a list of the bound types.
   List get _types;
 
diff --git a/tests/language/nnbd/flow_analysis/local_boolean_implicitly_typed_test.dart b/tests/language/nnbd/flow_analysis/local_boolean_implicitly_typed_test.dart
new file mode 100644
index 0000000..4038020
--- /dev/null
+++ b/tests/language/nnbd/flow_analysis/local_boolean_implicitly_typed_test.dart
@@ -0,0 +1,205 @@
+// Copyright (c) 2021, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// @dart=2.13
+
+import '../../static_type_helper.dart';
+
+// This test checks whether a local boolean variable can be used to perform type
+// promotion, if that variable is implicitly typed.
+//
+// Due to https://github.com/dart-lang/language/issues/1785, initializer
+// expressions on implicitly typed variables are ignored for the purposes of
+// type promotion (however, later assignments to those variables still do
+// influence promotion).  To avoid introducing breaking language changes, we
+// intend to preserve this behavior until a specific Dart language version.
+// This test verifies that for code that is not opted in to the newer behavior,
+// the old (buggy) behavior persists.
+
+parameterUnmodified(int? x) {
+  {
+    late final b = x != null;
+    // We wouldn't promote based on the initializers of late locals anyhow,
+    // because we don't know when they execute.
+    if (b) x.expectStaticType<Exactly<int?>>();
+  }
+  {
+    late final b;
+    b = x != null;
+    if (b) x.expectStaticType<Exactly<int>>();
+  }
+  {
+    late var b = x != null;
+    // We wouldn't promote based on the initializers of late locals anyhow,
+    // because we don't know when they execute.
+    if (b) x.expectStaticType<Exactly<int?>>();
+  }
+  {
+    late var b;
+    b = x != null;
+    if (b) x.expectStaticType<Exactly<int>>();
+  }
+  {
+    final b = x != null;
+    if (b) x.expectStaticType<Exactly<int?>>();
+  }
+  {
+    final b;
+    b = x != null;
+    if (b) x.expectStaticType<Exactly<int>>();
+  }
+  {
+    var b = x != null;
+    if (b) x.expectStaticType<Exactly<int?>>();
+  }
+  {
+    var b;
+    b = x != null;
+    if (b) x.expectStaticType<Exactly<int>>();
+  }
+}
+
+parameterModifiedLater(int? x, int? y) {
+  x = y;
+  {
+    late final b = x != null;
+    // We wouldn't promote based on the initializers of late locals anyhow,
+    // because we don't know when they execute.
+    if (b) x.expectStaticType<Exactly<int?>>();
+  }
+  {
+    late final b;
+    b = x != null;
+    if (b) x.expectStaticType<Exactly<int>>();
+  }
+  {
+    late var b = x != null;
+    // We wouldn't promote based on the initializers of late locals anyhow,
+    // because we don't know when they execute.
+    if (b) x.expectStaticType<Exactly<int?>>();
+  }
+  {
+    late var b;
+    b = x != null;
+    if (b) x.expectStaticType<Exactly<int>>();
+  }
+  {
+    final b = x != null;
+    if (b) x.expectStaticType<Exactly<int?>>();
+  }
+  {
+    final b;
+    b = x != null;
+    if (b) x.expectStaticType<Exactly<int>>();
+  }
+  {
+    var b = x != null;
+    if (b) x.expectStaticType<Exactly<int?>>();
+  }
+  {
+    var b;
+    b = x != null;
+    if (b) x.expectStaticType<Exactly<int>>();
+  }
+}
+
+localVariableInitialized(int? y) {
+  int? x = y;
+  {
+    late final b = x != null;
+    // We wouldn't promote based on the initializers of late locals anyhow,
+    // because we don't know when they execute.
+    if (b) x.expectStaticType<Exactly<int?>>();
+  }
+  {
+    late final b;
+    b = x != null;
+    if (b) x.expectStaticType<Exactly<int>>();
+  }
+  {
+    late var b = x != null;
+    // We wouldn't promote based on the initializers of late locals anyhow,
+    // because we don't know when they execute.
+    if (b) x.expectStaticType<Exactly<int?>>();
+  }
+  {
+    late var b;
+    b = x != null;
+    if (b) x.expectStaticType<Exactly<int>>();
+  }
+  {
+    final b = x != null;
+    if (b) x.expectStaticType<Exactly<int?>>();
+  }
+  {
+    final b;
+    b = x != null;
+    if (b) x.expectStaticType<Exactly<int>>();
+  }
+  {
+    var b = x != null;
+    if (b) x.expectStaticType<Exactly<int?>>();
+  }
+  {
+    var b;
+    b = x != null;
+    if (b) x.expectStaticType<Exactly<int>>();
+  }
+}
+
+localVariableModifiedLater(int? y) {
+  int? x;
+  x = y;
+  {
+    late final b = x != null;
+    // We wouldn't promote based on the initializers of late locals anyhow,
+    // because we don't know when they execute.
+    if (b) x.expectStaticType<Exactly<int?>>();
+  }
+  {
+    late final b;
+    b = x != null;
+    if (b) x.expectStaticType<Exactly<int>>();
+  }
+  {
+    late var b = x != null;
+    // We wouldn't promote based on the initializers of late locals anyhow,
+    // because we don't know when they execute.
+    if (b) x.expectStaticType<Exactly<int?>>();
+  }
+  {
+    late var b;
+    b = x != null;
+    if (b) x.expectStaticType<Exactly<int>>();
+  }
+  {
+    final b = x != null;
+    if (b) x.expectStaticType<Exactly<int?>>();
+  }
+  {
+    final b;
+    b = x != null;
+    if (b) x.expectStaticType<Exactly<int>>();
+  }
+  {
+    var b = x != null;
+    if (b) x.expectStaticType<Exactly<int?>>();
+  }
+  {
+    var b;
+    b = x != null;
+    if (b) x.expectStaticType<Exactly<int>>();
+  }
+}
+
+main() {
+  parameterUnmodified(null);
+  parameterUnmodified(0);
+  parameterModifiedLater(null, null);
+  parameterModifiedLater(null, 0);
+  localVariableInitialized(null);
+  localVariableInitialized(0);
+  localVariableModifiedLater(null);
+  localVariableModifiedLater(0);
+}
diff --git a/tools/VERSION b/tools/VERSION
index 39cb874..4109408 100644
--- a/tools/VERSION
+++ b/tools/VERSION
@@ -27,5 +27,5 @@
 MAJOR 2
 MINOR 15
 PATCH 0
-PRERELEASE 56
+PRERELEASE 57
 PRERELEASE_PATCH 0
\ No newline at end of file