Refactored treatment of closure variables in dart2js CPS.

pkg/compiler/lib/src/cps_ir/shrinking_reductions.dart

 // Copyright (c) 2014, 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.
 
 part of dart2js.optimizers;
 
 /**
  * [[ShrinkingReducer]] applies shrinking reductions to CPS terms as described
  * in 'Compiling with Continuations, Continued' by Andrew Kennedy.
  */
@@ skipping 292 matching lines @@
 
 /// Traverses the CPS term and sets node.parent for each visited node.
 class ParentVisitor extends RecursiveVisitor {
 
   processFieldDefinition(FieldDefinition node) {
     node.body.parent = node;
   }
 
   processFunctionDefinition(FunctionDefinition node) {
     node.body.parent = node;
-    node.parameters.forEach((Parameter p) => p.parent = node);
+    node.parameters.forEach((Definition p) => p.parent = node);
   }
 
   // Expressions.
 
   processLetPrim(LetPrim node) {
     node.primitive.parent = node;
     node.body.parent = node;
   }
 
   processLetCont(LetCont node) {
@@ skipping 126 matching lines @@
   }
 
   String toString() => "$kind: $node";
 }
 
 /// A dummy class used solely to mark nodes as deleted once they are removed
 /// from a term.
 class _DeletedNode extends Node {
   accept(_) => null;
 }