Change core lib, dart2js, and more for new optional parameters syntax

lib/compiler/samples/leap/leap_leg.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.
 
 compilerIsolate(port) {
   Runner runner = new Runner();
   runner.init();
 
   port.receive((msg, replyTo) {
     replyTo.send(runner.update(msg));
@@ skipping 238 matching lines @@
   }
 
   reportWarning(Node node, var message) {
     print(message);
   }
 
   reportError(Node node, var message) {
     cancel(message.toString(), node);
   }
 
-  void cancel([String reason, Node node, token, instruction, element]) {
+  void cancel(String reason, {Node node, token, instruction, element}) {
     print(reason);
   }
 
   Element runSelective(Script script) {
     Stopwatch sw = new Stopwatch()..start();
     Element e;
     try {
       e = runCompilerSelective(script);
     } on CompilerCancelledException catch (exception) {
       log(exception.toString());
       log('compilation failed');
       return null;
     }
     log('compilation succeeded: ${sw.elapsedInMs()}ms');
     return e;
   }
 
   LibraryElement runCompilerSelective(Script script) {
     mainApp = new LibraryElement(script);
 
     universe.libraries.remove(script.uri.toString());
     Element element;
     withCurrentElement(mainApp, () {
         scanner.scan(mainApp);
       });
     return mainApp;
   }
 }