Don't rely on ecs->wait_for_more.

	Don't rely on ecs->wait_for_more.

	* infrun.c (proceed): Clear the stepping state, set
	previous_inferior_ptid and clear infwait state.
	(wait_for_inferior): Don't clear the stepping state, set
	previous_inferior_ptid, or clear the infwait state here.
	(fetch_inferior_event): Don't clear the stepping state, set
	previous_inferior_ptid, or clear the infwait state here.  Don't
	condition on wait_for_more.