tree-vect-data-refs.c (vect_get_data_access_cost): Get prologue cost vector and pass it to vect_get_load_cost.

2018-04-26  Richard Biener  <rguenther@suse.de>

	* tree-vect-data-refs.c (vect_get_data_access_cost): Get
	prologue cost vector and pass it to vect_get_load_cost.
	(vect_get_peeling_costs_all_drs): Likewise.
	(vect_peeling_hash_get_lowest_cost): Likewise.
	(vect_enhance_data_refs_alignment): Likewise.

From-SVN: r259668