fix int64 sunindextype bug on windows
MSVC compiler has __int64 available for 64-bit integer.
@@ -111,6 +111,8 @@ typedef long double realtype;
#if __STDC_VERSION__ >= 199901L
typedef int64_t sunindextype;
+#elif _MSC_VER
+typedef __int64 sunindextype;
#else
typedef long int sunindextype;
#endif
