re PR tree-optimization/91162 (ICE: tree check: expected class 'type', have 'exceptional' (error_mark) in useless_type_conversion_p, at gimple-expr.c:86 (error: invalid 'PHI' argument))

2019-07-15  Richard Biener  <rguenther@suse.de>

	PR middle-end/91162
	* tree-cfg.c (move_block_to_fn): When releasing a virtual PHI
	node make sure to replace all uses with something valid.

	* gcc.dg/autopar/pr91162.c: New testcase.

From-SVN: r273492