Change intl to use new pub layout

pkg/intl/lib/message_lookup_local.dart

 // 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.
 
 /**
  * Message/plural format library with locale support. This can have different
  * implementations based on the mechanism for finding the localized versions
  * of messages. This version expects them to be in a library named e.g.
  * 'messages_en_US'. The prefix is set in the [initializeMessages] call, which
  * must be made for a locale before any lookups can be done.
@@ skipping 110 matching lines @@
       MethodMirror localized = messagesForThisLocale.functions[name];
       if (localized == null) return message_str;
       result = messagesForThisLocale.invoke(localized.simpleName, args);
       }
     finally {
       _lookupInProgress = false;
     }
     return result.value.reflectee;
   }
 }