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

tools/testing/dart/test_suite.dart

Index: tools/testing/dart/test_suite.dart
diff --git a/tools/testing/dart/test_suite.dart b/tools/testing/dart/test_suite.dart
index 74c4297d0c67aa4d800bc3ccefcc59667d69cf0a..97803ac1656c25a17070a9a58f351d990c3385c8 100644
--- a/tools/testing/dart/test_suite.dart
+++ b/tools/testing/dart/test_suite.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_suite");
 
+#import("dart:io");
 #import("status_file_parser.dart");
 #import("test_runner.dart");
 #import("multitest.dart");