tree-ssa-threadupdate.c (determine_bb_domination_status): Always check if BB is a successor of LOOP->header and return NONDOMINATING if...

	* tree-ssa-threadupdate.c (determine_bb_domination_status): Always
	check if BB is a successor of LOOP->header and return NONDOMINATING
	if it is not, regardless of ENABLE_CHECKING.

From-SVN: r172004