Elements. Return ExecutableElementImpl2 from ExecutableElement2OrMember.baseElement

Change-Id: I2878d65f04e5e1c6fe0e3f6691fedf4532e16d55
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/420260
Reviewed-by: Paul Berry <paulberry@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>

pkg/analyzer/lib/src/dart/element/element.dart

@@ -3606,6 +3606,9 @@ class EnumElementImpl2 extends InterfaceElementImpl2 implements EnumElement2 {
 /// Common base class for all analyzer-internal classes that implement
 /// `ExecutableElement2`.
 abstract class ExecutableElement2OrMember implements ExecutableElement2 {
+  @override
+  ExecutableElementImpl2 get baseElement;
+
   @override
   List<FormalParameterElementMixin> get formalParameters;
 
@@ -3826,7 +3829,7 @@ abstract class ExecutableElementImpl extends _ExistingElementImpl
 abstract class ExecutableElementImpl2 extends FunctionTypedElementImpl2
     implements ExecutableElement2OrMember {
   @override
-  ExecutableElement2 get baseElement => this;
+  ExecutableElementImpl2 get baseElement => this;
 
   @override
   List<Element2> get children2 => [
@@ -5438,7 +5441,10 @@ class GenericFunctionTypeElementImpl2 extends FunctionTypedElementImpl2
 /// Common base class for all analyzer-internal classes that implement
 /// [GetterElement].
 abstract class GetterElement2OrMember
-    implements PropertyAccessorElement2OrMember, GetterElement {}
+    implements PropertyAccessorElement2OrMember, GetterElement {
+  @override
+  GetterElementImpl get baseElement;
+}
 
 class GetterElementImpl extends PropertyAccessorElementImpl2
     with
@@ -5461,7 +5467,7 @@ class GetterElementImpl extends PropertyAccessorElementImpl2
   }
 
   @override
-  GetterElement get baseElement => this;
+  GetterElementImpl get baseElement => this;
 
   @override
   SetterElement? get correspondingSetter2 =>
@@ -8358,7 +8364,10 @@ final class MetadataImpl implements Metadata {
 /// Common base class for all analyzer-internal classes that implement
 /// `MethodElement2`.
 abstract class MethodElement2OrMember
-    implements MethodElement2, ExecutableElement2OrMember {}
+    implements MethodElement2, ExecutableElement2OrMember {
+  @override
+  MethodElementImpl2 get baseElement;
+}
 
 class MethodElementImpl extends ExecutableElementImpl
     implements MethodElementOrMember, MethodFragment {
@@ -8472,7 +8481,7 @@ class MethodElementImpl2 extends ExecutableElementImpl2
   MethodElementImpl2(this.name3, this.firstFragment);
 
   @override
-  MethodElement2 get baseElement => this;
+  MethodElementImpl2 get baseElement => this;
 
   @override
   Element2? get enclosingElement2 =>
@@ -10027,6 +10036,9 @@ abstract class PromotableElementImpl2 extends VariableElementImpl2
 /// `PropertyAccessorElement2`.
 abstract class PropertyAccessorElement2OrMember
     implements PropertyAccessorElement2, ExecutableElement2OrMember {
+  @override
+  PropertyAccessorElementImpl2 get baseElement;
+
   @override
   PropertyInducingElement2OrMember? get variable3;
 }
@@ -10143,7 +10155,7 @@ sealed class PropertyAccessorElementImpl extends ExecutableElementImpl
 abstract class PropertyAccessorElementImpl2 extends ExecutableElementImpl2
     implements PropertyAccessorElement2OrMember {
   @override
-  PropertyAccessorElement2 get baseElement => this;
+  PropertyAccessorElementImpl2 get baseElement => this;
 
   @override
   Element2 get enclosingElement2 => firstFragment.enclosingFragment.element;
@@ -10571,7 +10583,10 @@ abstract class PropertyInducingElementTypeInference {
 /// Common base class for all analyzer-internal classes that implement
 /// [SetterElement].
 abstract class SetterElement2OrMember
-    implements PropertyAccessorElement2OrMember, SetterElement {}
+    implements PropertyAccessorElement2OrMember, SetterElement {
+  @override
+  SetterElementImpl get baseElement;
+}
 
 class SetterElementImpl extends PropertyAccessorElementImpl2
     with
@@ -10594,7 +10609,7 @@ class SetterElementImpl extends PropertyAccessorElementImpl2
   }
 
   @override
-  SetterElement get baseElement => this;
+  SetterElementImpl get baseElement => this;
 
   @override
   GetterElement? get correspondingGetter2 =>
@@ -10856,7 +10871,7 @@ class TopLevelFunctionElementImpl extends ExecutableElementImpl2
   }
 
   @override
-  TopLevelFunctionElement get baseElement => this;
+  TopLevelFunctionElementImpl get baseElement => this;
 
   @override
   LibraryElementImpl get enclosingElement2 {

pkg/analyzer/lib/src/dart/element/member.dart

@@ -718,7 +718,7 @@ class GetterMember extends PropertyAccessorMember
   }) : super._();
 
   @override
-  GetterElement get baseElement => _element2;
+  GetterElementImpl get baseElement => _element2;
 
   @override
   SetterElement2OrMember? get correspondingSetter2 {
@@ -760,7 +760,9 @@ class GetterMember extends PropertyAccessorMember
       variable2.asElement2 as PropertyInducingElement2OrMember?;
 
   @override
-  GetterElement get _element2 => declaration.asElement2 as GetterElement;
+  GetterElementImpl get _element2 {
+    return declaration.asElement2 as GetterElementImpl;
+  }
 
   @override
   T? accept2<T>(ElementVisitor2<T> visitor) {
@@ -1492,7 +1494,7 @@ class SetterMember extends PropertyAccessorMember
   }) : super._();
 
   @override
-  SetterElement get baseElement => _element2;
+  SetterElementImpl get baseElement => _element2;
 
   @override
   GetterElement2OrMember? get correspondingGetter2 {
@@ -1534,7 +1536,9 @@ class SetterMember extends PropertyAccessorMember
       variable2.asElement2 as PropertyInducingElement2OrMember?;
 
   @override
-  SetterElement get _element2 => declaration.asElement2 as SetterElement;
+  SetterElementImpl get _element2 {
+    return declaration.asElement2 as SetterElementImpl;
+  }
 
   @override
   T? accept2<T>(ElementVisitor2<T> visitor) {