Win32 build fix

src/runtime.cc

 // Copyright 2012 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 783 matching lines @@
 
 static void ArrayBufferWeakCallback(v8::Isolate* external_isolate,
                                     Persistent<Value> object,
                                     void* data) {
   Isolate* isolate = reinterpret_cast<Isolate*>(external_isolate);
   HandleScope scope(isolate);
   Handle<Object> internal_object = Utils::OpenHandle(*object);
 
   size_t allocated_length = ArrayBufferAllocatedLength(
       isolate, JSArrayBuffer::cast(*internal_object));
-  isolate->heap()->AdjustAmountOfExternalAllocatedMemory(-allocated_length);
+  isolate->heap()->AdjustAmountOfExternalAllocatedMemory(
+      -static_cast<intptr_t>(allocated_length));
   if (data != NULL)
     free(data);
   object.Dispose(external_isolate);
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_ArrayBufferInitialize) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 2);
   CONVERT_ARG_HANDLE_CHECKED(JSArrayBuffer, holder, 0);
@@ skipping 12334 matching lines @@
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     isolate->counters()->gc_last_resort_from_js()->Increment();
     isolate->heap()->CollectAllGarbage(Heap::kNoGCFlags,
                                        "Runtime::PerformGC");
   }
 }
 
 
 } }  // namespace v8::internal