Fix http_requested_uri_test for Win/Mac.

tests/standalone/io/http_requested_uri_test.dart

 // Copyright (c) 2013, 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.
 
 import "package:expect/expect.dart";
 import "package:async_helper/async_helper.dart";
 import "dart:async";
 import "dart:io";
 
 const PATH = '/path?a=b#c';
 
 void test(String expected, Map headers) {
   asyncStart();
-  HttpServer.bind("127.0.0.1", 0).then((server) {
+  HttpServer.bind("localhost", 0).then((server) {

[Søren Gjesse, 2014/01/09 08:53:57]

Wheren't the use of localhost the source of sporadic errors on our Mac builders
(once in a while the lookup would return the IPv4 address instead of the IPv6
one)?

[Søren Gjesse, 2014/01/09 09:00:56]

Thinking about this again the issue was only there if two processes where used.

     expected = expected.replaceAll('%PORT', server.port.toString());
     server.listen((request) {
       Expect.equals("$expected$PATH",
                     request.requestedUri.toString());
       request.response.close();
     });
     HttpClient client = new HttpClient();
     client.get("localhost", server.port, PATH)
       .then((request) {
         for (var v in headers.keys) {
@@ skipping 12 matching lines @@
       });
   });
 }
 
 
 void main() {
   test('http://localhost:%PORT', {});
   test('https://localhost:%PORT', {'x-forwarded-proto': 'https'});
   test('ws://localhost:%PORT', {'x-forwarded-proto': 'ws'});
   test('http://my-host:321', {'x-forwarded-host': 'my-host:321'});
-  test('http://127.0.0.1:%PORT', {'host': null});
+  test('http://localhost:%PORT', {'host': null});
 }