re PR tree-optimization/90610 (526.blender_r miscompared on znver1 with -Ofast -march=native since r271463)

2019-05-27  Richard Biener  <rguenther@suse.de>

	PR middle-end/90610
	* match.pd (vec_perm): Avoid clobbering op0 when not generating
	a bit-insert.

From-SVN: r271652