Use elements/types in constants/values

pkg/compiler/lib/src/js_emitter/interceptor_stub_generator.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 InterceptorStubGenerator {
   final Compiler compiler;
   final Namer namer;
   final JavaScriptBackend backend;
@@ skipping 343 matching lines @@
   jsAst.ArrayInitializer generateTypeToInterceptorMap() {
     // TODO(sra): Perhaps inject a constant instead?
     CustomElementsAnalysis analysis = backend.customElementsAnalysis;
     if (!analysis.needsTable) return null;
 
     List<jsAst.Expression> elements = <jsAst.Expression>[];
     JavaScriptConstantCompiler handler = backend.constants;
     List<ConstantValue> constants =
         handler.getConstantsForEmission(emitter.compareConstants);
     for (ConstantValue constant in constants) {
-      if (constant is TypeConstantValue) {
-        TypeConstantValue typeConstant = constant;
-        Element element = typeConstant.representedType.element;
+      if (constant is TypeConstantValue &&
+          constant.representedType is ResolutionInterfaceType) {
+        ResolutionInterfaceType type = constant.representedType;
+        Element element = type.element;
         if (element is ClassElement) {
           ClassElement classElement = element;
           if (!analysis.needsClass(classElement)) continue;
 
           elements.add(emitter.constantReference(constant));
           elements.add(backend.emitter.interceptorClassAccess(classElement));
 
           // Create JavaScript Object map for by-name lookup of generative
           // constructors.  For example, the class A has three generative
           // constructors
@@ skipping 17 matching lines @@
 
           var map = new jsAst.ObjectInitializer(properties);
           elements.add(map);
         }
       }
     }
 
     return new jsAst.ArrayInitializer(elements);
   }
 }