Fix build problems on Windows 64-bit by casting.

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 2289 matching lines @@
 Object* Heap::CopyCode(Code* code, Vector<byte> reloc_info) {
   int new_body_size = RoundUp(code->instruction_size() + reloc_info.length(),
                               kObjectAlignment);
 
   int sinfo_size = code->sinfo_size();
 
   int new_obj_size = Code::SizeFor(new_body_size, sinfo_size);
 
   Address old_addr = code->address();
 
-  int relocation_offset = code->relocation_start() - old_addr;
+  size_t relocation_offset =
+      static_cast<size_t>(code->relocation_start() - old_addr);
 
   Object* result;
   if (new_obj_size > MaxObjectSizeInPagedSpace()) {
     result = lo_space_->AllocateRawCode(new_obj_size);
   } else {
     result = code_space_->AllocateRaw(new_obj_size);
   }
 
   if (result->IsFailure()) return result;
 
@@ skipping 2059 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