re PR tree-optimization/85712 (ICE in all_phi_incrs_profitable_1 at gcc/gimple-ssa-strength-reduction.c:3479)

2018-05-25  Bill Schmidt  <wschmidt@linux.ibm.com>

	PR tree-optimization/85712
	* gimple-ssa-strength-reduction.c (replace_one_candidate): Skip if
	this candidate has already been replaced in-situ by a copy.

From-SVN: r260772