2019-04-16  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/56049
	* tree-ssa-loop-im.c (mem_ref_hasher::equal): Elide alias-set
	equality check if alias-set zero will prevail.

	* gfortran.dg/pr56049.f90: New testcase.

From-SVN: r270378