Add 'part of' in dart2js code.

lib/compiler/implementation/util/util.dart

Index: lib/compiler/implementation/util/util.dart
diff --git a/lib/compiler/implementation/util/util.dart b/lib/compiler/implementation/util/util.dart
index f00d146b5f455885cfe51d682a4f9ab8e5a38d82..ef3b0f63967d080d320c22d8fb7b1e38a6c5a660 100644
--- a/lib/compiler/implementation/util/util.dart
+++ b/lib/compiler/implementation/util/util.dart
@@ -2,9 +2,11 @@
 // 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.
 
-#library('org.dartlang.compiler.util');
-#import('util_implementation.dart');
-#source('link.dart');
+library org_dartlang_compiler_util;
+
+import 'util_implementation.dart';
+
+part 'link.dart';
 
 /**
  * Tagging interface for classes from which source spans can be generated.