Add 'part of' in dart2js code.

lib/compiler/implementation/universe/function_set.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 universe;
+
 // TODO(kasperl): This actually holds getters and setters just fine
 // too and stricly they aren't functions. Maybe this needs a better
 // name -- something like ElementSet seems a bit too generic.
 class FunctionSet extends PartialTypeTree {
 
   FunctionSet(Compiler compiler) : super(compiler);
 
   FunctionSetNode newSpecializedNode(ClassElement type)
       => new FunctionSetNode(type);
 
@@ skipping 114 matching lines @@
 }
 
 class FunctionSetNode extends PartialTypeTreeNode {
 
   final Map<SourceString, Element> membersByName;
 
   FunctionSetNode(ClassElement type) : super(type),
       membersByName = new Map<SourceString, Element>();
 
 }