Use ConstExp for storing constants.

sdk/lib/_internal/compiler/implementation/js_emitter/code_emitter_task.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 dart2js.js_emitter;
 
 const USE_NEW_EMITTER = const bool.fromEnvironment("dart2js.use.new.emitter");
 
 /**
  * Generates the code for all used classes in the program. Static fields (even
@@ skipping 917 matching lines @@
   void emitStaticNonFinalFieldInitializations(CodeBuffer buffer) {
     JavaScriptConstantCompiler handler = backend.constants;
     Iterable<VariableElement> staticNonFinalFields =
         handler.getStaticNonFinalFieldsForEmission();
     for (Element element in Elements.sortedByPosition(staticNonFinalFields)) {
       // [:interceptedNames:] is handled in [emitInterceptedNames].
       if (element == backend.interceptedNames) continue;
       // `mapTypeToInterceptor` is handled in [emitMapTypeToInterceptor].
       if (element == backend.mapTypeToInterceptor) continue;
       compiler.withCurrentElement(element, () {
-        Constant initialValue = handler.getInitialValueFor(element);
+        Constant initialValue = handler.getInitialValueFor(element).value;
         jsAst.Expression init =
           js('$isolateProperties.# = #',
               [namer.getNameOfGlobalField(element),
                constantEmitter.referenceInInitializationContext(initialValue)]);
         buffer.write(jsAst.prettyPrint(init, compiler,
                                        monitor: compiler.dumpInfoTask));
         buffer.write('$N');
       });
     }
   }
@@ skipping 1134 matching lines @@
     for (Element element in compiler.enqueuer.codegen.newlyEnqueuedElements) {
       if (element.isInstanceMember) {
         cachedClassBuilders.remove(element.enclosingClass);
 
         nativeEmitter.cachedBuilders.remove(element.enclosingClass);
 
       }
     }
   }
 }