Split dart:builtin into dart:builtin and dart:io.

tools/testing/dart/test_runner.dart

Index: tools/testing/dart/test_runner.dart
diff --git a/tools/testing/dart/test_runner.dart b/tools/testing/dart/test_runner.dart
index 8acf632e86aa4a28988bf37697beb0a47962597f..6e29b7109c9852d58ec24f5acfc2f148e360b47a 100644
--- a/tools/testing/dart/test_runner.dart
+++ b/tools/testing/dart/test_runner.dart
@@ -1,9 +1,10 @@
-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // 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("test_runner");
 
+#import("dart:io");
 #import("status_file_parser.dart");
 #import("test_progress.dart");
 #import("test_suite.dart");