re PR middle-end/80539 (gcc ICE at -O2 and above on valid code on x86_64-linux-gnu in "chrec_fold_plus_poly_poly")

2017-04-27  Richard Biener  <rguenther@suse.de>

	PR middle-end/80539
	* tree-chrec.c (chrec_fold_plus_poly_poly): Deal with not
	being in loop-closed SSA form conservatively.
	(chrec_fold_multiply_poly_poly): Likewise.

	* gcc.dg/torture/pr80539.c: New testcase.

From-SVN: r247322