Add kind to ConstantValue.

pkg/compiler/lib/src/js_backend/constant_emitter.dart

 // Copyright (c) 2012, 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 js_backend;
 
 typedef jsAst.Expression _ConstantReferenceGenerator(ConstantValue constant);
 
 typedef jsAst.Expression _ConstantListGenerator(jsAst.Expression array);
 
@@ skipping 251 matching lines @@
   }
 
   @override
   jsAst.Expression visitInterceptor(InterceptorConstantValue constant, [_]) {
     ClassElement interceptorClass = constant.dispatchedType.element;
     return backend.emitter.interceptorPrototypeAccess(interceptorClass);
   }
 
   @override
   jsAst.Expression visitSynthetic(SyntheticConstantValue constant, [_]) {
-    switch (constant.kind) {
+    switch (constant.valueKind) {
       case SyntheticConstantKind.DUMMY_INTERCEPTOR:
       case SyntheticConstantKind.EMPTY_VALUE:
         return new jsAst.LiteralNumber('0');
       case SyntheticConstantKind.TYPEVARIABLE_REFERENCE:
       case SyntheticConstantKind.NAME:
         return constant.payload;
       default:
         reporter.internalError(NO_LOCATION_SPANNABLE,
             "Unexpected DummyConstantKind ${constant.kind}");
         return null;
@@ skipping 39 matching lines @@
           [value, argumentList]);
     }
     return value;
   }
 
   @override
   jsAst.Expression visitDeferred(DeferredConstantValue constant, [_]) {
     return constantReferenceGenerator(constant.referenced);
   }
 }