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

dart/tests/language/import_core_prefix_test.dart

Index: dart/tests/language/import_core_prefix_test.dart
diff --git a/dart/tests/language/import_core_prefix_test.dart b/dart/tests/language/import_core_prefix_test.dart
index 16f9559f15a1772e86b7085d537ee6ade39b6f6f..782fdf1b704dc39080e43575f7dba1fbee3a7e34 100644
--- a/dart/tests/language/import_core_prefix_test.dart
+++ b/dart/tests/language/import_core_prefix_test.dart
@@ -3,8 +3,8 @@
 // BSD-style license that can be found in the LICENSE file.
 // Test explicit import of dart:core in the source code..
 
-library ImportCorePrefixTest;
-import "dart:core" as mycore;
+#library("ImportCorePrefixTest.dart");
+#import("dart:core", prefix:"mycore");
 
 void main() {
   var test = new mycore.Map<mycore.int,mycore.String>();