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

tests/standalone/src/ProcessStderrTest.dart

Index: tests/standalone/src/ProcessStderrTest.dart
diff --git a/tests/standalone/src/ProcessStderrTest.dart b/tests/standalone/src/ProcessStderrTest.dart
index 17637eb008cf0a6a343d85e0c9830bfe425c518b..bd5ae604cdf7740810f12cd708d836f3250094d0 100644
--- a/tests/standalone/src/ProcessStderrTest.dart
+++ b/tests/standalone/src/ProcessStderrTest.dart
@@ -1,4 +1,4 @@
-// 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.
 //
@@ -10,6 +10,7 @@
 // VMOptions=--short_socket_read --short_socket_write
 
 #library("ProcessStderrTest");
+#import("dart:io");
 #source("ProcessTestUtil.dart");
 
 void test(Process process) {