dart2js cps: Remove default call to visit return continuation.

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

 // Copyright (c) 2013, 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.
 library dart2js.ir_nodes;
 
 import 'dart:collection';
 import 'cps_fragment.dart' show CpsFragment;
 import '../constants/values.dart' as values;
 import '../dart_types.dart' show DartType, InterfaceType, TypeVariableType;
 import '../elements/elements.dart';
@@ skipping 1998 matching lines @@
 
   visit(Node node) => node.accept(this);
 
   processReference(Reference ref) {}
 
   processFunctionDefinition(FunctionDefinition node) {}
   visitFunctionDefinition(FunctionDefinition node) {
     processFunctionDefinition(node);
     if (node.thisParameter != null) visit(node.thisParameter);
     node.parameters.forEach(visit);
-    visit(node.returnContinuation);
     visit(node.body);
   }
 
   processContinuation(Continuation node) {}
   visitContinuation(Continuation node) {
     processContinuation(node);
     node.parameters.forEach(visit);
     if (node.body != null) visit(node.body);
   }
 
@@ skipping 340 matching lines @@
       } else {
         _processBlock(traverseContinuation(cont));
       }
     });
   }
 
   visitFunctionDefinition(FunctionDefinition node) {
     processFunctionDefinition(node);
     if (node.thisParameter != null) visit(node.thisParameter);
     node.parameters.forEach(visit);
-    visit(node.returnContinuation);
     visit(node.body);
   }
 
   visitContinuation(Continuation cont) {
     if (cont.isReturnContinuation) {
       traverseContinuation(cont);
     } else {
       int initialHeight = _stack.length;
       Expression body = traverseContinuation(cont);
       _trampoline(body, initialHeight: initialHeight);
@@ skipping 441 matching lines @@
     plug(new Branch.loose(_definitions.getCopy(node.condition),
         _copies[node.trueContinuation.definition],
         _copies[node.falseContinuation.definition])
       ..isStrictCheck = node.isStrictCheck);
   }
 
   visitUnreachable(Unreachable node) {
     plug(new Unreachable());
   }
 }