Added support for pagers that fault to suspend and become zombies
along with all the threads that they manage. Zombie killing is to
be done at a later time, from this special zombie queue.
The implementation works same as a suspension, with the added action
that the thread is moved to a queue in kernel container.
Issues:
- A page-faulting thread suspends if receives -1 from pager page fault ipc.
This is fine if pager is about to delete the thread, but it is not if
it is a buggy pager.
- Need to find a way to completely get rid of suspended pager.
- A method of deleting suspended tasks could remedy both cases above.
