Fix MinGW64 build.

src/globals.h

Index: src/globals.h
diff --git a/src/globals.h b/src/globals.h
index 9f137808021248cb10d8d44ff8dc7fc2cc580686..e53cc81d6c2e58249b91bdb319e8dafa6961a8dd 100644
--- a/src/globals.h
+++ b/src/globals.h
@@ -175,27 +175,27 @@ typedef byte* Address;
 // than defining __STDC_CONSTANT_MACROS before including <stdint.h>, and it
 // works on compilers that don't have it (like MSVC).
 #if V8_HOST_ARCH_64_BIT
-#ifdef _MSC_VER
+#if defined(_MSC_VER)
 #define V8_UINT64_C(x)  (x ## UI64)
 #define V8_INT64_C(x)   (x ## I64)
 #define V8_INTPTR_C(x)  (x ## I64)
 #define V8_PTR_PREFIX "ll"
-#else  // _MSC_VER
+#elif defined(__MINGW64__)
+#define V8_UINT64_C(x)  (x ## ULL)
+#define V8_INT64_C(x)   (x ## LL)
+#define V8_INTPTR_C(x)  (x ## LL)
+#define V8_PTR_PREFIX "I64"
+#else
 #define V8_UINT64_C(x)  (x ## UL)
 #define V8_INT64_C(x)   (x ## L)
 #define V8_INTPTR_C(x)  (x ## L)
 #define V8_PTR_PREFIX "l"
-#endif  // _MSC_VER
+#endif
 #else  // V8_HOST_ARCH_64_BIT
 #define V8_INTPTR_C(x)  (x)
 #define V8_PTR_PREFIX ""
 #endif  // V8_HOST_ARCH_64_BIT
 
-#ifdef __MINGW64__
-#undef V8_PTR_PREFIX
-#define V8_PTR_PREFIX "I64"
-#endif  // __MINGW64__
-
 // The following macro works on both 32 and 64-bit platforms.
 // Usage: instead of writing 0x1234567890123456
 //      write V8_2PART_UINT64_C(0x12345678,90123456);