* cprop.c (implicit_set_cond_p): Assume nothing about COND, move

	* cprop.c (implicit_set_cond_p): Assume nothing about COND, move
	checks on form of COND from find_implicit_sets to here.
	(find_implicit_sets): Cleanup control flow. Split critical edges
	if it exposes implicit sets.  Allocate/resize implicit_sets as
	necessary.
	(one_cprop_pass): Only delete unreachable blocks if local_cprop_pass
	changed something.  Run df_analyze after find_implicit_sets if any
	edges were split.  Do not allocate implicit_sets here.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@171946 138bc75d-0d04-0410-961f-82ee72b054a4