[serializer] fix hash function for hashmap used for serializing.

src/address-map.h

 // Copyright 2015 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_ADDRESS_MAP_H_
 #define V8_ADDRESS_MAP_H_
 
 #include "include/v8.h"
 #include "src/assert-scope.h"
 #include "src/base/hashmap.h"
@@ skipping 20 matching lines @@
     Entry* entry = Lookup(key, Hash(key));
     if (entry == nullptr) return Nothing<uint32_t>();
     return Just(entry->value);
   }
 
  private:
   static uintptr_t Key(Type value) {
     return reinterpret_cast<uintptr_t>(value);
   }
 
-  static uint32_t Hash(uintptr_t key) {
-    return static_cast<uint32_t>(key >> kPointerSizeLog2);
-  }
+  static uint32_t Hash(uintptr_t key) { return static_cast<uint32_t>(key); }
 };
 
 class AddressToIndexHashMap : public PointerToIndexHashMap<Address> {};
 class HeapObjectToIndexHashMap : public PointerToIndexHashMap<HeapObject*> {};
 
 class RootIndexMap {
  public:
   explicit RootIndexMap(Isolate* isolate);
 
   static const int kInvalidRootIndex = -1;
@@ skipping 164 matching lines @@
   DisallowHeapAllocation no_allocation_;
   HeapObjectToIndexHashMap map_;
   int attached_reference_index_;
   DISALLOW_COPY_AND_ASSIGN(SerializerReferenceMap);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_ADDRESS_MAP_H_