Function pthread_rwlock_init 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn pthread_rwlock_init(
    rwlock: *mut pthread_rwlock_t,
    attr: *const pthread_rwlockattr_t,
) -> c_int

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