Revert "Force use of "%I64d" format for 64 bit ints on MinGW."

This reverts commit 52d01c2f.

the UINT64_FORMAT bit broke the b uildfarm, so I'm reverting the whole thing pending further investigation.

src/include/port/win32.h

@@ -88,19 +88,6 @@
 #define PGDLLEXPORT
 #endif
 
-/*
- * MinGW compilers accept both "%I64d" and "%lld" for 64 bit ints,
- * but whine about the latter, so force the former, regardless of what
- * configure found.
- */
-#if __GNUC__
-#ifdef INT64_FORMAT
-#undef INT64_FORMAT
-#undef UINT64_FORMAT
-#endif
-#define INT64_FORMAT "%I64d"
-#define UINT64_FORMAT "%I64u"
-#endif
 
 /*
  *	IPC defines