rem: static void deliver_signal(struct thread *t, int signal)
add: deliver_signal(struct thread *t, int signal)
context: static void deliver_signal(struct thread *t, int signal){//	dprintf("deliver_signal: thread %p (%d), signal %d\n", t, t->id, signal);	switch(signal) {		case SIG_KILL:			t->pending_signals |= SIG_KILL;			switch(t->state) {				case B_THREAD_SUSPENDED:					t->state = B_THREAD_READY;					t->next_state = B_THREAD_READY;					thread_enqueue_run_q(t);					break;				case B_THREAD_WAITING:					sem_interrupt_thread(t);					break;				default:					;			}			break;		default:			t->pending_signals |= signal;	}}