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

dart/lib/compiler/implementation/source_map_builder.dart

Index: dart/lib/compiler/implementation/source_map_builder.dart
diff --git a/dart/lib/compiler/implementation/source_map_builder.dart b/dart/lib/compiler/implementation/source_map_builder.dart
index 0670ee20218d1d3d9b5ebb8acc7abbf91a7cf778..a29b0fe3f428380545ab329a073da3dfeb8f2001 100644
--- a/dart/lib/compiler/implementation/source_map_builder.dart
+++ b/dart/lib/compiler/implementation/source_map_builder.dart
@@ -2,12 +2,12 @@
 // 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 source_map_builder;
+#library('source_map_builder');
 
-import 'dart:json';
+#import('dart:json');
 
-import 'scanner/scannerlib.dart';
-import 'source_file.dart';
+#import('scanner/scannerlib.dart');
+#import('source_file.dart');
 
 class SourceMapBuilder {
   static const int VLQ_BASE_SHIFT = 5;