MUTEX_WAITER
__ww_mutex_die(struct MUTEX *lock, struct MUTEX_WAITER *waiter,
struct MUTEX_WAITER *cur;
__ww_mutex_check_kill(struct MUTEX *lock, struct MUTEX_WAITER *waiter,
struct MUTEX_WAITER *cur;
__ww_mutex_add_waiter(struct MUTEX_WAITER *waiter,
struct MUTEX_WAITER *cur, *pos = NULL;