0.pre8.78

0.pre8.78
	More locking fixes exposed by using a real SMP system
	... gencgc: gc_alloc_update_page_tables touches global data
	    so needs wrapping in free_pages_lock
	... gencgc_handle_wp_violation: we can get two CPUs in this
	    routine at once, so it would be nice if the second one
 	    didn't barf if it found the first had been here already

	Found an eliminated another THREAD_CONTROL_STACK_SIZE use