use the selected clock from the condattr for pthread_cond_timedwait

src/internal/pthread_impl.h

@@ -48,6 +48,7 @@ struct pthread {
 #define _m_waiters __u.__i[2]
 #define _m_owner __u.__i[3]
 #define _c_block __u.__i[0]
+#define _c_clock __u.__i[1]
 #define _rw_wrlock __u.__i[0]
 #define _rw_readers __u.__i[1]
 #define _rw_waiters __u.__i[2]

src/thread/pthread_cond_init.c

@@ -3,5 +3,6 @@
 int pthread_cond_init(pthread_cond_t *c, const pthread_condattr_t *a)
 {
 	memset(c, 0, sizeof *c);
+	if (a) c->_c_clock = *a & 0x7fffffff;
 	return 0;
 }

src/thread/pthread_cond_timedwait.c

@@ -15,7 +15,7 @@ int pthread_cond_timedwait(pthread_cond_t *c, pthread_mutex_t *m, const struct t
 	if ((r=pthread_mutex_unlock(m))) return r;
 
 	CANCELPT(1);
-	e = __timedwait(&c->_c_block, 1, CLOCK_REALTIME, ts, 0);
+	e = __timedwait(&c->_c_block, 1, c->_c_clock, ts, 0);
 	CANCELPT(0);
 
 	pthread_cleanup_pop(0);