Don't supply host names for the fixed internet addresses

tests/standalone/io/internet_address_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 'dart:io';
 
 import "package:expect/expect.dart";
 
 void testDefaultAddresses() {
   var loopback4 = InternetAddress.LOOPBACK_IP_V4;
   Expect.isNotNull(loopback4);
   Expect.equals(InternetAddressType.IP_V4, loopback4.type);
-  Expect.equals("localhost", loopback4.host);
+  Expect.equals("127.0.0.1", loopback4.host);
   Expect.equals("127.0.0.1", loopback4.address);
 
   var loopback6 = InternetAddress.LOOPBACK_IP_V6;
   Expect.isNotNull(loopback6);
   Expect.equals(InternetAddressType.IP_V6, loopback6.type);
-  Expect.equals("ip6-localhost", loopback6.host);
+  Expect.equals("::1", loopback6.host);
   Expect.equals("::1", loopback6.address);
 
   var any4 = InternetAddress.ANY_IP_V4;
   Expect.isNotNull(any4);
   Expect.equals(InternetAddressType.IP_V4, any4.type);
   Expect.equals("0.0.0.0", any4.host);
   Expect.equals("0.0.0.0", any4.address);
 
   var any6 = InternetAddress.ANY_IP_V6;
   Expect.isNotNull(any6);
@@ skipping 28 matching lines @@
       Expect.notEquals('127.0.0.1', addr.host);
     });
   });
 }
 
 void main() {
   testDefaultAddresses();
   testLookup();
   testReverseLookup();
 }