util.h: add stdint basic type definitions

MS C compiler v15 doesn't have stdint.h. Add basic int types those are defined
in stdint.h.

mercurial/util.h

@@ -121,7 +121,12 typedef PyObject *(*ssizeargfunc)(PyObje
 #ifdef _MSC_VER
 /* msvc 6.0 has problems */
 #define inline __inline
+typedef signed char int8_t;
+typedef short int16_t;
+typedef long int32_t;
+typedef __int64 int64_t;
 typedef unsigned char uint8_t;
+typedef unsigned short uint16_t;
 typedef unsigned long uint32_t;
 typedef unsigned __int64 uint64_t;
 #else