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

tests/standalone/src/SocketExceptionTest.dart

Index: tests/standalone/src/SocketExceptionTest.dart
diff --git a/tests/standalone/src/SocketExceptionTest.dart b/tests/standalone/src/SocketExceptionTest.dart
index 562bae4779c06e1d51c4e4171c7acbdb52bc12ec..18748a0337636e0a4db62d45ccd63681573254ae 100644
--- a/tests/standalone/src/SocketExceptionTest.dart
+++ b/tests/standalone/src/SocketExceptionTest.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.
 //
 // Tests socket exceptions.
 
+#import("dart:io");
+
 class SocketExceptionTest {
 
   static final PORT = 0;