Get rid of MSVC's __int64

Use either int64_t, uint64_t or long long and unsigned long long, defined as per C++11 standard

Minecraft.Client/PSVita/PSVitaExtras/zconf.h

@@ -485,7 +485,7 @@ typedef uLong FAR uLongf;
 #  define z_off64_t off64_t
 #else
 #  if defined(_WIN32) && !defined(__GNUC__) && !defined(Z_SOLO)
-#    define z_off64_t __int64
+#    define z_off64_t int64_t
 #  else
 #    define z_off64_t z_off_t
 #  endif