[turbofan] First version of loop peeling.

src/compiler/node.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_NODE_H_
 #define V8_COMPILER_NODE_H_
 
 #include "src/compiler/opcodes.h"
 #include "src/compiler/operator.h"
 #include "src/types-inl.h"
@@ skipping 266 matching lines @@
   bool operator!=(const Edge& other) { return !(*this == other); }
 
   void UpdateTo(Node* new_to) { input_->Update(new_to); }
 
  private:
   friend class Node::UseEdges::iterator;
   friend class Node::InputEdges::iterator;
 
   explicit Edge(Node::Input* input) : input_(input) { DCHECK_NOT_NULL(input); }
 
-  Node::Input* const input_;
+  Node::Input* input_;
 };
 
 
 // A forward iterator to visit the edges for the input dependencies of a node.
 class Node::InputEdges::iterator FINAL {
  public:
   typedef std::forward_iterator_tag iterator_category;
   typedef int difference_type;
   typedef Edge value_type;
   typedef Edge* pointer;
@@ skipping 179 matching lines @@
 
 void Node::ReplaceInput(int index, Node* new_to) {
   GetInputRecordPtr(index)->Update(new_to);
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_NODE_H_