* infrun.c (wait_for_inferior): Invalidate registers and overlay

	* infrun.c (wait_for_inferior): Invalidate registers and overlay
	cache every time before calling target_wait.
	(handle_inferior_event): Make static. Always reset waiton_ptid.
	Never call registers_changed.
	(prepare_to_wait): Do not invaliate registers or overlay cache
	(moved to wait_for_inferior).  Do not reset waiton_ptid (moved
	to handle_inferior_event).
	(fetch_inferior_event): Remove check for always-true condition.