Include superclasses of classes only needed for rti

pkg/compiler/lib/src/js_emitter/model.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 dart2js.new_js_emitter.model;
 
 import '../constants/values.dart' show ConstantValue;
 import '../deferred_load.dart' show OutputUnit;
 import '../elements/entities.dart';
 import '../js/js.dart' as js show Expression, Name, Statement, TokenFinalizer;
@@ skipping 264 matching lines @@
   Class get superclass => _superclass;
 
   void setSuperclass(Class superclass) {
     _superclass = superclass;
   }
 
   js.Name get superclassName => superclass == null ? null : superclass.name;
 
   int get superclassHolderIndex =>
       (superclass == null) ? 0 : superclass.holder.index;
+
+  String toString() => 'Class(${element.name})';
 }
 
 class MixinApplication extends Class {
   Class _mixinClass;
 
   MixinApplication(
       ClassEntity element,
       js.Name name,
       Holder holder,
       List<Field> instanceFields,
@@ skipping 232 matching lines @@
             functionType: functionType);
 
   bool get isStatic => true;
 }
 
 class StaticStubMethod extends StubMethod implements StaticMethod {
   Holder holder;
   StaticStubMethod(js.Name name, this.holder, js.Expression code)
       : super(name, code);
 }