Add a flag to the element model to identify mixin applications.

pkg/analyzer/lib/src/generated/element_handle.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.
 
 // This code was auto-generated, is not intended to be edited, and is subject to
 // significant change. Please see the README file for more information.
 
 library engine.element_handle;
 
 import 'ast.dart';
@@ skipping 43 matching lines @@
   @override
   List<InterfaceType> get interfaces => actualElement.interfaces;
 
   @override
   bool get isAbstract => actualElement.isAbstract;
 
   @override
   bool get isEnum => actualElement.isEnum;
 
   @override
+  bool get isMixinApplication => actualElement.isMixinApplication;
+
+  @override
   bool get isOrInheritsProxy => actualElement.isOrInheritsProxy;
 
   @override
   bool get isProxy => actualElement.isProxy;
 
   @override
   bool get isTypedef => actualElement.isTypedef;
 
   @override
   bool get isValidMixin => actualElement.isValidMixin;
@@ skipping 1020 matching lines @@
   DartType get type => actualElement.type;
 }
 /**
  * TODO(scheglov) invalid implementation
  */
 class WeakReference<T> {
   final T value;
   WeakReference(this.value);
   T get() => value;
 }