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

tests/standalone/src/DirectoryTest.dart

Index: tests/standalone/src/DirectoryTest.dart
diff --git a/tests/standalone/src/DirectoryTest.dart b/tests/standalone/src/DirectoryTest.dart
index 2a735e5f4b195ca06773110be22c7370c8eab3c2..846b018f1ad2f544ca87d0edebf5eb490c96a7aa 100644
--- a/tests/standalone/src/DirectoryTest.dart
+++ b/tests/standalone/src/DirectoryTest.dart
@@ -1,9 +1,11 @@
-// 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.
 //
 // Directory listing test.
 
+#import("dart:io");
+
 class DirectoryTest {
   static void testListing() {
     bool listedDir = false;