Use CommonNodeCache for heap constants in ChangeLowering.

src/compiler/node-cache.h

 // Copyright 2014 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_CACHE_H_
 #define V8_COMPILER_NODE_CACHE_H_
 
-#include "src/v8.h"
-
-#include "src/compiler/node.h"
+#include "src/base/macros.h"
 
 namespace v8 {
 namespace internal {
+
+// Forward declarations.
+class Zone;
+
 namespace compiler {
 
+// Forward declarations.
+class Node;
+
 // A cache for nodes based on a key. Useful for implementing canonicalization of
 // nodes such as constants, parameters, etc.
 template <typename Key>
 class NodeCache {
  public:
   explicit NodeCache(int max = 256) : entries_(NULL), size_(0), max_(max) {}
 
   // Search for node associated with {key} and return a pointer to a memory
   // location in this cache that stores an entry for the key. If the location
   // returned by this method contains a non-NULL node, the caller can use that
   // node. Otherwise it is the responsibility of the caller to fill the entry
   // with a new node.
   // Note that a previous cache entry may be overwritten if the cache becomes
   // too full or encounters too many hash collisions.
   Node** Find(Zone* zone, Key key);
 
  private:
   struct Entry {
     Key key_;
     Node* value_;
   };
 
   Entry* entries_;  // lazily-allocated hash entries.
-  int32_t size_;
-  int32_t max_;
+  int size_;
+  int max_;
 
   bool Resize(Zone* zone);
+
+  DISALLOW_COPY_AND_ASSIGN(NodeCache);
 };
 
 // Various default cache types.
+typedef NodeCache<int32_t> Int32NodeCache;
 typedef NodeCache<int64_t> Int64NodeCache;
-typedef NodeCache<int32_t> Int32NodeCache;
-typedef NodeCache<void*> PtrNodeCache;
-}
-}
-}  // namespace v8::internal::compiler
+typedef NodeCache<intptr_t> IntPtrNodeCache;
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8
 
 #endif  // V8_COMPILER_NODE_CACHE_H_