tree-optimization/105484 - VEC_SET and EH

tree-optimization/105484 - VEC_SET and EH

When the IL representation of VEC_SET is marked as throwing
(unnecessarily), we need to clean that when replacing it with
the .VEC_SET internal function call which cannot throw.

2022-05-05  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/105484
	* gimple-isel.cc (gimple_expand_vec_set_expr): Clean EH, return
	whether the CFG changed.
	(gimple_expand_vec_exprs): When the CFG changed, clean it up.

	* gcc.dg/torture/pr105484.c: New testcase.

(cherry picked from commit e1a41143a2e24c65d94364fd82b165ff71a759d8)