Updates dartc to recognize 'default' keyword on interface and updated factory method syntax

tests/stub-generator/src/MintMakerFullyIsolatedTest-generatedTest.dart

 // Copyright (c) 2011, 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.
 
 // IsolateStubs=MintMakerFullyIsolatedTest.dart:Mint,Purse,PowerfulPurse
 #library("MintMakerFullyIsolatedTest-generatedTest");
 #import("../../isolate/src/TestFramework.dart");
 
 /* class = Purse (tests/stub-generator/src/MintMakerFullyIsolatedTest.dart/MintMakerFullyIsolatedTest.dart: 9) */
 
@@ skipping 207 matching lines @@
 }
 interface Purse {
   Purse();
   int queryBalance();
   Purse$Proxy sproutPurse();
   // The deposit has not completed until the promise completes. If we
   // supported Promise<void> then this could use that.
   Promise<int> deposit(int amount, Purse$Proxy source);
 }
 
-interface PowerfulPurse extends Purse factory PurseImpl {
+interface PowerfulPurse extends Purse default PurseImpl {
   PowerfulPurse();
 
   void init(Mint$Proxy mint, int balance);
   // Return an int so we can wait for it to complete. Shame we can't
   // have a Promise<void>.
   int grab(int amount);
   Purse weak();
 }
 
-interface Mint factory MintImpl {
+interface Mint default MintImpl {
   Mint();
 
   Purse$Proxy createPurse(int balance);
   Promise<PowerfulPurse$Proxy> promote(Purse$Proxy purse);
 }
 
 // Because promises can't be used as keys in maps until they have
 // completed, provide a wrapper. Note that if any key promise fails to
 // resolve, then get()'s return may also fail to resolve. Right now, a
 // Proxy can also be used since it has (kludgily) been made to inherit
@@ skipping 250 matching lines @@
       expect.succeeded();
       print("##DONE##");
     });
   }
 
 }
 
 main() {
   runTests([MintMakerFullyIsolatedTest.testMain]);
 }