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

lib/compiler/implementation/resolved_visitor.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.
 
 abstract class ResolvedVisitor<R> extends Visitor<R> {
   TreeElements elements;
 
   ResolvedVisitor(this.elements);
 
   R visitSend(Send node) {
@@ skipping 34 matching lines @@
   }
 
   abstract R visitSuperSend(Send node);
   abstract R visitOperatorSend(Send node);
   abstract R visitGetterSend(Send node);
   abstract R visitClosureSend(Send node);
   abstract R visitDynamicSend(Send node);
   abstract R visitForeignSend(Send node);
   abstract R visitStaticSend(Send node);
 
-  abstract void internalError(String reason, [Node node]);
+  abstract void internalError(String reason, {Node node});
 
   R visitNode(Node node) {
-    internalError("Unhandled node", node);
+    internalError("Unhandled node", node: node);
   }
 }