re PR middle-end/89779 (internal compiler error: tree check: expected class ‘type...

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)

2019-03-21  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/89779
	* tree.c (tree_nop_conversion): Consolidate and fix defensive
	checks with respect to released SSA names now having error_mark_node
	type.
	* fold-const.c (operand_equal_p): Likewise.

	* gcc.dg/torture/pr89779.c: New testcase.

From-SVN: r269838