Revert "Parts must start with 'part of'" and "Attempt to fix VM build"

dart/lib/compiler/implementation/diagnostic_listener.dart

Index: dart/lib/compiler/implementation/diagnostic_listener.dart
diff --git a/dart/lib/compiler/implementation/diagnostic_listener.dart b/dart/lib/compiler/implementation/diagnostic_listener.dart
index 661397ed13411199cf63ffa17f2eeb2c5585868b..e684e9eb7e3a4e843e7b1aaf8017bd60daf4d67f 100644
--- a/dart/lib/compiler/implementation/diagnostic_listener.dart
+++ b/dart/lib/compiler/implementation/diagnostic_listener.dart
@@ -2,8 +2,6 @@
 // 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 parser;
-
 abstract class DiagnosticListener {
   // TODO(karlklose): replace cancel with better error reporting mechanism.
   void cancel(String reason, {node, token, instruction, element});