Fix two tests in InheritanceManger3

There are still two failing tests, but I wanted to get these in before
some code started depending on the broken behavior.

Change-Id: I50f0e282293e756409064491e74c64311fbdf707
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/388666
Reviewed-by: Konstantin Shcheglov <[email protected]>
Commit-Queue: Brian Wilkerson <[email protected]>

Author: bwilkerson

pkg/analyzer/lib/src/dart/element/inheritance_manager3.dart

@@ -351,7 +351,7 @@ class InheritanceManager3 {
       forMixinIndex: forMixinIndex,
       forSuper: forSuper,
     );
-    return element?.declaration.asElement2 as ExecutableElement2?;
+    return element?.asElement2 as ExecutableElement2?;
   }
 
   /// Returns the member with the given [name].
@@ -381,7 +381,7 @@ class InheritanceManager3 {
       forMixinIndex: forMixinIndex,
       forSuper: forSuper,
     );
-    return oldElement?.declaration.asElement2 as ExecutableElement2?;
+    return oldElement?.asElement2 as ExecutableElement2?;
   }
 
   /// Returns all members of mixins, superclasses, and interfaces that a member

pkg/analyzer/test/src/dart/element/inheritance_manager3_test.dart

@@ -1015,12 +1015,10 @@ class C extends B implements A {}
       concrete: true,
     )!;
     // TODO(scheglov): It would be nice to use `_assertGetMember`.
-    expect(member.baseElement,
-        same((findElement.method('foo', of: 'B') as MethodFragment).element));
+    expect(member.baseElement, same(findElement.method('foo', of: 'B')));
     expect(member.formalParameters[0].isCovariant, isTrue);
   }
 
-  @FailingTest(reason: 'Members need to implement `Element2` not `Fragment`')
   test_getMember_mixin_notMerge_replace() async {
     await resolveTestCode('''
 class A<T> {
@@ -1282,8 +1280,7 @@ class C extends B implements A {}
       concrete: true,
     )!;
     // TODO(scheglov): It would be nice to use `_assertGetMember`.
-    expect(member.baseElement,
-        same((findElement.setter('foo', of: 'B') as SetterFragment).element));
+    expect(member.baseElement, same(findElement.setter('foo', of: 'B')));
     expect(member.formalParameters[0].isCovariant, isTrue);
   }