tree-ssa-pre.c: Include alias.h.

tree-ssa-pre.c: Include alias.h.

2016-07-07  Richard Biener  <rguenther@suse.de>

	* tree-ssa-pre.c: Include alias.h.
	(compute_avail): If we have multiple VN_REFERENCEs with the
	same hashtable entry adjust that to make it a valid replacement
	for all of them with respect to alignment and aliasing
	when doing insertion.
	* tree-ssa-sccvn.h (vn_reference_operands_for_lookup): Declare.
	* tree-ssa-sccvn.c (vn_reference_operands_for_lookup): New function.

From-SVN: r238078