Add integer casts to make v8 compile without warnings on 64-bit Visual Studio

src/heap.cc

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 4093 matching lines @@
                                                   : "Mark-sweep";
   }
   return "Unknown GC";
 }
 
 
 int KeyedLookupCache::Hash(Map* map, String* name) {
   // Uses only lower 32 bits if pointers are larger.
   uintptr_t addr_hash =
       static_cast<uint32_t>(reinterpret_cast<uintptr_t>(map)) >> kMapHashShift;
-  return (addr_hash ^ name->Hash()) & kCapacityMask;
+  return static_cast<uint32_t>((addr_hash ^ name->Hash()) & kCapacityMask);
 }
 
 
 int KeyedLookupCache::Lookup(Map* map, String* name) {
   int index = Hash(map, name);
   Key& key = keys_[index];
   if ((key.map == map) && key.name->Equals(name)) {
     return field_offsets_[index];
   }
   return -1;
@@ skipping 94 matching lines @@
 void ExternalStringTable::TearDown() {
   new_space_strings_.Free();
   old_space_strings_.Free();
 }
 
 
 List<Object*> ExternalStringTable::new_space_strings_;
 List<Object*> ExternalStringTable::old_space_strings_;
 
 } }  // namespace v8::internal