re PR middle-end/89779 (internal compiler error: tree check: expected class ‘type’, have ‘exceptional’ (error_mark) in tree_nop_conversion_p, at tree.c:12798)

2019-03-25  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/89779
	* tree-ssa-loop-ivopts.c (remove_unused_ivs): Return
	to remove IV defs, delay actual removal.
	(tree_ssa_iv_optimize_loop): Likewise.  Avoid SCEV reset.
	(tree_ssa_iv_optimize): Remove eliminated IV defs at the
	very end, properly also reset loop control IV information.

From-SVN: r269914