Function pthread_mutex_getprioceiling 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn pthread_mutex_getprioceiling(
    mutex: *const pthread_mutex_t,
    prioceiling: *mut c_int,
) -> c_int

See https://pubs.opengroup.org/onlinepubs/9799919799/functions/pthread_mutex_getprioceiling.html.