tree-vect-loop-manip.c (slpeel_add_loop_guard): New param and mark new edge's irreducible flag accordign to it.

	* tree-vect-loop-manip.c (slpeel_add_loop_guard): New param and
	mark new edge's irreducible flag accordign to it.
	(vect_do_peeling): Check loop preheader edge's irreducible flag
	and pass it to function slpeel_add_loop_guard.
	gcc/testsuite
	* gcc.c-torture/compile/irreducible-loop.c: New.

From-SVN: r246540