Elements. For FormalParameterFragment enclosingFragment can be another FormalParameterFragment, not only ExecutableFragment.

Change-Id: I2aa32b088ad77a41e4b40d406488a12da126f52d
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/398945
Reviewed-by: Phil Quitslund <pquitslund@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
diff --git a/pkg/analyzer/lib/dart/element/element2.dart b/pkg/analyzer/lib/dart/element/element2.dart
index 8a55584..3aeb53b 100644
--- a/pkg/analyzer/lib/dart/element/element2.dart
+++ b/pkg/analyzer/lib/dart/element/element2.dart
@@ -2184,9 +2184,6 @@
   PromotableElement2 get element;
 
   @override
-  ExecutableFragment? get enclosingFragment;
-
-  @override
   PromotableFragment? get nextFragment;
 
   @override
diff --git a/pkg/analyzer/lib/src/dart/element/element.dart b/pkg/analyzer/lib/src/dart/element/element.dart
index 46b6141..2877ebd 100644
--- a/pkg/analyzer/lib/src/dart/element/element.dart
+++ b/pkg/analyzer/lib/src/dart/element/element.dart
@@ -8869,8 +8869,7 @@
   set element(FormalParameterElement element) => _element = element;
 
   @override
-  ExecutableFragment? get enclosingFragment =>
-      enclosingElement3 as ExecutableFragment?;
+  Fragment? get enclosingFragment => enclosingElement3 as Fragment?;
 
   @override
   bool get hasDefaultValue {