Fix warnings on Win64.

src/regexp-stack.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 63 matching lines @@
     DeleteArray(thread_local_.memory_);
     thread_local_ = ThreadLocal();
   }
 }
 
 
 Address RegExpStack::EnsureCapacity(size_t size) {
   if (size > kMaximumStackSize) return NULL;
   if (size < kMinimumStackSize) size = kMinimumStackSize;
   if (thread_local_.memory_size_ < size) {
-    Address new_memory = NewArray<byte>(size);
+    Address new_memory = NewArray<byte>(static_cast<int>(size));
     if (thread_local_.memory_size_ > 0) {
       // Copy original memory into top of new memory.
       memcpy(reinterpret_cast<void*>(
           new_memory + size - thread_local_.memory_size_),
              reinterpret_cast<void*>(thread_local_.memory_),
              thread_local_.memory_size_);
       DeleteArray(thread_local_.memory_);
     }
     thread_local_.memory_ = new_memory;
     thread_local_.memory_size_ = size;
     thread_local_.limit_ = new_memory + kStackLimitSlack * kPointerSize;
   }
   return thread_local_.memory_ + thread_local_.memory_size_;
 }
 
 
 RegExpStack::ThreadLocal RegExpStack::thread_local_;
 
 }}  // namespace v8::internal