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

tests/standalone/src/EchoServerTest.dart

Index: tests/standalone/src/EchoServerTest.dart
diff --git a/tests/standalone/src/EchoServerTest.dart b/tests/standalone/src/EchoServerTest.dart
index 2213ac3c53d106508e28a30df720d1c2ee416e12..23ad2850940ba22263caf0e57c7a929973835339 100644
--- a/tests/standalone/src/EchoServerTest.dart
+++ b/tests/standalone/src/EchoServerTest.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("EchoServerTest");
+#import("dart:io");
 #source("TestingServer.dart");
 
 class EchoServerTest {