winpthreads: mutex.c: improve `pthread_mutex_timedlock`

POSIX[1] does not specify behavior when the second argument to
`pthread_mutex_timedlock` is NULL; assume it is always non-NULL.

Follow POSIX[1] specification and fail with EINVAL if `tv_nsec` field of passed
`struct timespec` is less than zero or greater than or equal to 1000000000.

Replace uses of `unsigned long long` with more MSVC-friendly `unsigned __int64`.

Cast `patience` variable to `DWORD` when calling `pthread_mutex_lock_intern`;
this avoids MSVC warning C4244.

[1] https://pubs.opengroup.org/onlinepubs/9799919799.2024edition/functions/pthread_mutex_clocklock.html

Signed-off-by: Kirill Makurin <maiddaisuki@outlook.com>
Signed-off-by: LIU Hao <lh_mouse@126.com>

mingw-w64-libraries/winpthreads/src/mutex.c

diff --git a/mingw-w64-libraries/winpthreads/src/mutex.c b/mingw-w64-libraries/winpthreads/src/mutex.c
index 77f045b..d27c1e2 100644
--- a/mingw-w64-libraries/winpthreads/src/mutex.c
+++ b/mingw-w64-libraries/winpthreads/src/mutex.c
@@ -234,17 +234,27 @@
 
 int pthread_mutex_timedlock64(pthread_mutex_t *m, const struct _timespec64 *ts)
 {
-  unsigned long long patience;
-  if (ts != NULL) {
-    unsigned long long end = _pthread_time_in_ms_from_timespec(ts);
-    unsigned long long now = _pthread_time_in_ms();
-    patience = end > now ? end - now : 0;
-    if (patience > 0xffffffff)
-      patience = INFINITE;
-  } else {
+  /**
+   * The pthread_mutex_timedlock() function shall fail if:
+   *
+   * [EINVAL]
+   *  The process or thread would have blocked, and the abstime parameter
+   *  specified a nanoseconds field value less than zero or greater than
+   *  or equal to 1000 million.
+   */
+  if (ts->tv_nsec < 0 || ts->tv_nsec >= 1000000000) {
+    return EINVAL;
+  }
+
+  unsigned __int64 end = _pthread_time_in_ms_from_timespec (ts);
+  unsigned __int64 now = _pthread_time_in_ms ();
+  unsigned __int64 patience = end > now ? end - now : 0;
+
+  if (patience > 0xffffffff) {
     patience = INFINITE;
   }
-  return pthread_mutex_lock_intern(m, patience);
+
+  return pthread_mutex_lock_intern(m, (DWORD) patience);
 }
 
 int pthread_mutex_timedlock32(pthread_mutex_t *m, const struct _timespec32 *ts)