fixes #27586, prefer context type in generic inference

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

 // Copyright (c) 2014, 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.
 
 library analyzer.src.dart.element.member;
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/constant/value.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
@@ skipping 916 matching lines @@
   @override
   Element get enclosingElement => baseElement.enclosingElement;
 
   @override
   int get hashCode => baseElement.hashCode;
 
   @override
   TypeParameterType get type => _type;
 
   @override
+  bool operator ==(Object other) =>
+      other is TypeParameterMember && baseElement == other.baseElement;
+
+  @override
   /*=T*/ accept/*<T>*/(ElementVisitor<dynamic/*=T*/ > visitor) =>
       visitor.visitTypeParameterElement(this);
 
   /**
    * If the given [parameter]'s type is different when any type parameters from
    * the defining type's declaration are replaced with the actual type
    * arguments from the [definingType], create a parameter member representing
    * the given parameter. Return the member that was created, or the base
    * parameter if no member was created.
    */
@@ skipping 102 matching lines @@
   DartObject computeConstantValue() => baseElement.computeConstantValue();
 
   @override
   void visitChildren(ElementVisitor visitor) {
     // TODO(brianwilkerson) We need to finish implementing the accessors used
     // below so that we can safely invoke them.
     super.visitChildren(visitor);
     baseElement.initializer?.accept(visitor);
   }
 }