sokol_time.h: add _stm prefix to int64_muldiv()

sokol_time.h

@@ -199,7 +199,7 @@ static _stm_state_t _stm;
     see https://gist.github.com/jspohr/3dc4f00033d79ec5bdaf67bc46c813e3
 */
 #if defined(_WIN32) || (defined(__APPLE__) && defined(__MACH__))
-_SOKOL_PRIVATE int64_t int64_muldiv(int64_t value, int64_t numer, int64_t denom) {
+_SOKOL_PRIVATE int64_t _stm_int64_muldiv(int64_t value, int64_t numer, int64_t denom) {
     int64_t q = value / denom;
     int64_t r = value % denom;
     return q * numer + r * numer / denom;
@@ -230,10 +230,10 @@ SOKOL_API_IMPL uint64_t stm_now(void) {
     #if defined(_WIN32)
         LARGE_INTEGER qpc_t;
         QueryPerformanceCounter(&qpc_t);
-        now = (uint64_t) int64_muldiv(qpc_t.QuadPart - _stm.start.QuadPart, 1000000000, _stm.freq.QuadPart);
+        now = (uint64_t) _stm_int64_muldiv(qpc_t.QuadPart - _stm.start.QuadPart, 1000000000, _stm.freq.QuadPart);
     #elif defined(__APPLE__) && defined(__MACH__)
         const uint64_t mach_now = mach_absolute_time() - _stm.start;
-        now = (uint64_t) int64_muldiv((int64_t)mach_now, (int64_t)_stm.timebase.numer, (int64_t)_stm.timebase.denom);
+        now = (uint64_t) _stm_int64_muldiv((int64_t)mach_now, (int64_t)_stm.timebase.numer, (int64_t)_stm.timebase.denom);
     #elif defined(__EMSCRIPTEN__)
         double js_now = emscripten_get_now() - _stm.start;
         now = (uint64_t) (js_now * 1000000.0);