add pthread_cond_timedwait_relative_np

Author: joboet

libc-test/semver/apple.txt

@@ -2090,6 +2090,7 @@ pthread_attr_setschedpolicy
 pthread_attr_setscope
 pthread_attr_setstackaddr
 pthread_cancel
+pthread_cond_timedwait_relative_np
 pthread_condattr_getpshared
 pthread_condattr_setpshared
 pthread_cpu_number_np

src/unix/bsd/apple/mod.rs

@@ -5179,6 +5179,11 @@ extern "C" {
         newp: *mut c_void,
         newlen: size_t,
     ) -> c_int;
+    pub fn pthread_cond_timedwait_relative_np(
+        cond: *mut pthread_cond_t,
+        lock: *mut pthread_mutex_t,
+        timeout: *const crate::timespec,
+    ) -> c_int;
     pub fn pthread_once(
         once_control: *mut crate::pthread_once_t,
         init_routine: Option<unsafe extern "C" fn()>,