re PR middle-end/53844 (GCC generates suboptimal code for unused members of classes in some cases on multiple targets.)

2012-07-04  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/53844
	* tree-ssa-dse.c (dse_possible_dead_store_p): Properly handle
	the loop virtual PHI.

	* g++.dg/tree-ssa/pr53844.C: New testcase.

From-SVN: r189256