Support enums in dart2js.

pkg/analyzer2dart/lib/src/modely.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.
 
 part of analyzer2dart.element_converter;
 
 
 /// Base [dart2js.Element] implementation for converted analyzer elements.
 class ElementY extends dart2js.Element {
   final ElementConverter converter;
@@ skipping 628 matching lines @@
   @override
   dart2js.DartType get supertype => unsupported('supertype');
 
   @override
   int get supertypeLoadState => unsupported('supertypeLoadState');
 
   @override
   validateConstructorLookupResults(selector,  result, noMatch) {
     unsupported('validateConstructorLookupResults');
   }
+
+  @override
+  bool get isEnumClass => unsupported('isEnum');
 }
 
 class TypedefElementY extends TypeDeclarationElementY
     implements dart2js.TypedefElement {
 
   analyzer.FunctionTypeAliasElement get element => super.element;
 
   dart2js.ElementKind get kind => dart2js.ElementKind.TYPEDEF;
 
   TypedefElementY(ElementConverter converter,
@@ skipping 114 matching lines @@
 
   @override
   bool get isRedirectingFactory => unsupported('isRedirectingFactory');
 
   @override
   get nestedClosures => unsupported('nestedClosures');
 
   @override
   get type => unsupported('type');
 }