Add loop_vinfo argument to vect_get_loop_mask

Add loop_vinfo argument to vect_get_loop_mask

This adds a loop_vinfo argument for future use, making the next
patch smaller.

	* tree-vectorizer.h (vect_get_loop_mask): Add loop_vec_info
	argument.
	* tree-vect-loop.cc (vect_get_loop_mask): Likewise.
	(vectorize_fold_left_reduction): Adjust.
	(vect_transform_reduction): Likewise.
	(vectorizable_live_operation): Likewise.
	* tree-vect-stmts.cc (vectorizable_call): Likewise.
	(vectorizable_operation): Likewise.
	(vectorizable_store): Likewise.
	(vectorizable_load): Likewise.
	(vectorizable_condition): Likewise.