Fix compilation with recent MinGW64 versions.

src/v8dll-main.cc

 // Copyright 2011 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 12 matching lines @@
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 // The GYP based build ends up defining USING_V8_SHARED when compiling this
 // file.
 #undef USING_V8_SHARED
 #include "../include/v8.h"
 
-#ifdef WIN32
-#include <windows.h>  // NOLINT
+#if V8_OS_WIN
+#include "win32-headers.h"
 
 extern "C" {
 BOOL WINAPI DllMain(HANDLE hinstDLL,
                     DWORD dwReason,
                     LPVOID lpvReserved) {
   // Do nothing.
   return TRUE;
 }
 }
-#endif
+#endif  // V8_OS_WIN