re PR tree-optimization/81987 (ICE in verify_ssa with -O3 -march=skylake-avx512)

re PR tree-optimization/81987 (ICE in verify_ssa with -O3 -march=skylake-avx512)

[gcc]

2017-08-30  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>

	PR tree-optimization/81987
	* gimple-ssa-strength-reduction.c (insert_initializers): Don't
	insert an initializer in a location not dominated by the stride
	definition.

[gcc/testsuite]

2017-08-30  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>

	PR tree-optimization/81987
	* g++.dg/torture/pr81987.C: New file.

From-SVN: r251547