Add 'part of' in dart2js code.

lib/compiler/implementation/universe/function_set.dart

Index: lib/compiler/implementation/universe/function_set.dart
diff --git a/lib/compiler/implementation/universe/function_set.dart b/lib/compiler/implementation/universe/function_set.dart
index 8dd7d58ea2f7d7a25f99722e61aaf659e50904b9..f55ad502d4e89c66d66fa45c17abc3045bc23a15 100644
--- a/lib/compiler/implementation/universe/function_set.dart
+++ b/lib/compiler/implementation/universe/function_set.dart
@@ -2,6 +2,8 @@
 // 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.