[19/46] Make vect_dr_stmt return a stmt_vec_info

[19/46] Make vect_dr_stmt return a stmt_vec_info

This patch makes vect_dr_stmt return a stmt_vec_info instead of a
gimple stmt.  Rather than retain a separate gimple stmt variable
in cases where both existed, the patch replaces uses of the gimple
variable with the uses of the stmt_vec_info.  Later patches do this
more generally.

Many things that are keyed off a data_reference would these days
be better keyed off a stmt_vec_info, but it's more convenient
to do that later in the series.  The vect_dr_size calls that are
left over do still benefit from this patch.

2018-07-31  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* tree-vectorizer.h (vect_dr_stmt): Return a stmt_vec_info rather
	than a gimple stmt.
	* tree-vect-data-refs.c (vect_analyze_data_ref_dependence)
	(vect_slp_analyze_data_ref_dependence, vect_record_base_alignments)
	(vect_calculate_target_alignmentm, vect_compute_data_ref_alignment)
	(vect_update_misalignment_for_peel, vect_verify_datarefs_alignment)
	(vector_alignment_reachable_p, vect_get_data_access_cost)
	(vect_get_peeling_costs_all_drs, vect_peeling_hash_get_lowest_cost)
	(vect_peeling_supportable, vect_enhance_data_refs_alignment)
	(vect_find_same_alignment_drs, vect_analyze_data_refs_alignment)
	(vect_analyze_group_access_1, vect_analyze_group_access)
	(vect_analyze_data_ref_access, vect_analyze_data_ref_accesses)
	(vect_vfa_access_size, vect_small_gap_p, vect_analyze_data_refs)
	(vect_supportable_dr_alignment): Remove vinfo_for_stmt from the
	result of vect_dr_stmt and use the stmt_vec_info instead of
	the associated gimple stmt.
	* tree-vect-loop-manip.c (get_misalign_in_elems): Likewise.
	(vect_gen_prolog_loop_niters): Likewise.
	* tree-vect-loop.c (vect_analyze_loop_2): Likewise.

From-SVN: r263134