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

tests/standalone/src/SocketManyConnectionsTest.dart

Index: tests/standalone/src/SocketManyConnectionsTest.dart
diff --git a/tests/standalone/src/SocketManyConnectionsTest.dart b/tests/standalone/src/SocketManyConnectionsTest.dart
index f53af7f249eee0d62f9de6dc6d00eb0b8eec4c95..15b5fe8c3f07ee0d06fdf4da42c4bddfd13a663a 100644
--- a/tests/standalone/src/SocketManyConnectionsTest.dart
+++ b/tests/standalone/src/SocketManyConnectionsTest.dart
@@ -1,10 +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.
 //
 // Test creating a large number of socket connections.
 
 #library("SocketManyConnectionsTest");
+#import("dart:io");
 #source("TestingServer.dart");
 
 final CONNECTIONS = 200;