rem: is_kill_signal_pending()
add: is_kill_signal_pending(void)
context: is_kill_signal_pending(){	bool result;	struct thread *thread = thread_get_current_thread();		cpu_status state = disable_interrupts();	GRAB_THREAD_LOCK();	result = (thread->sig_pending & KILL_SIGNALS);	RELEASE_THREAD_LOCK();	restore_interrupts(state);	return result;}