Use closure conversion in new dart2js backend.

pkg/compiler/lib/src/js_emitter/old_emitter/emitter.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 dart2js.js_emitter;
 
 
 class OldEmitter implements Emitter {
   final Compiler compiler;
   final CodeEmitterTask task;
@@ skipping 213 matching lines @@
   @override
   jsAst.PropertyAccess interceptorClassAccess(ClassElement element) {
     return globalPropertyAccess(element);
   }
 
   @override
   jsAst.PropertyAccess typeAccess(Element element) {
     return globalPropertyAccess(element);
   }
 
+  @override
+  jsAst.PropertyAccess closureClassConstructorAccess(ClosureClassElement e) {
+    return globalPropertyAccess(e);
+  }
+
   List<jsAst.Statement> buildTrivialNsmHandlers(){
     return nsmEmitter.buildTrivialNsmHandlers();
   }
 
   jsAst.FunctionDeclaration get generateAccessorFunction {
     const RANGE1_SIZE = RANGE1_LAST - RANGE1_FIRST + 1;
     const RANGE2_SIZE = RANGE2_LAST - RANGE2_FIRST + 1;
     const RANGE1_ADJUST = - (FIRST_FIELD_CODE - RANGE1_FIRST);
     const RANGE2_ADJUST = - (FIRST_FIELD_CODE + RANGE1_SIZE - RANGE2_FIRST);
     const RANGE3_ADJUST =
@@ skipping 1848 matching lines @@
     for (Element element in compiler.enqueuer.codegen.newlyEnqueuedElements) {
       if (element.isInstanceMember) {
         cachedClassBuilders.remove(element.enclosingClass);
 
         nativeEmitter.cachedBuilders.remove(element.enclosingClass);
 
       }
     }
   }
 }