Clean up node iteration

src/compiler/generic-algorithm.h

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_GENERIC_ALGORITHM_H_
 #define V8_COMPILER_GENERIC_ALGORITHM_H_
 
 #include <stack>
 
 #include "src/zone-containers.h"
@@ skipping 52 matching lines @@
           }
           stack.pop();
           if (stack.empty()) {
             if (++root_begin == root_end) return;
             current = *root_begin;
             break;
           }
           post_order_node = Traits::from(stack.top().first);
           visit = true;
         } else {
-          visitor->PreEdge(Traits::from(top.first), top.first.edge().index(),
+          visitor->PreEdge(Traits::from(top.first), (*top.first).index(),
                            Traits::to(top.first));
           current = Traits::to(top.first);
           if (!GetVisited(&visited, current->id())) break;
         }
         top = stack.top();
-        visitor->PostEdge(Traits::from(top.first), top.first.edge().index(),
+        visitor->PostEdge(Traits::from(top.first), (*top.first).index(),
                           Traits::to(top.first));
         ++stack.top().first;
       }
     }
   }
 
   template <class Visitor, class Traits>
   static void Visit(Graph* graph, Zone* zone, typename Traits::Node* current,
                     Visitor* visitor) {
     typename Traits::Node* array[] = {current};
@@ skipping 19 matching lines @@
   static bool GetVisited(BoolVector* visited, int id) {
     if (id >= static_cast<int>(visited->size())) return false;
     return visited->at(id);
   }
 };
 }
 }
 }  // namespace v8::internal::compiler
 
 #endif  // V8_COMPILER_GENERIC_ALGORITHM_H_