dart2js: don't pass the supername to visitFields.

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 1304 matching lines @@
   }
 
   void emitLibraries(Iterable<LibraryElement> libraries) {
     if (libraries.isEmpty) return;
 
     // TODO(karlklose): document what kinds of fields this loop adds to the
     // library class builder.
     for (LibraryElement element in libraries) {
       LibraryElement library = element;
       ClassBuilder builder = new ClassBuilder(library, namer);
-      if (classEmitter.emitFields(library, builder, null, emitStatics: true)) {
+      if (classEmitter.emitFields(library, builder, emitStatics: true)) {
         jsAst.ObjectInitializer initializer = builder.toObjectInitializer();
         compiler.dumpInfoTask.registerElementAst(builder.element, initializer);
         getElementDescriptor(library).properties.addAll(initializer.properties);
       }
     }
   }
 
   void emitTypedefs() {
     OutputUnit mainOutputUnit = compiler.deferredLoadTask.mainOutputUnit;
 
@@ skipping 677 matching lines @@
     for (Element element in compiler.enqueuer.codegen.newlyEnqueuedElements) {
       if (element.isInstanceMember) {
         cachedClassBuilders.remove(element.enclosingClass);
 
         nativeEmitter.cachedBuilders.remove(element.enclosingClass);
 
       }
     }
   }
 }