Make {SLP_TREE,STMT_VINFO}_VEC_STMTS a vector of gimple *

Make {SLP_TREE,STMT_VINFO}_VEC_STMTS a vector of gimple *

This makes {SLP_TREE,STMT_VINFO}_VEC_STMTS a vector of gimple * and
not allocate a stmt_vec_info for vectorizer generated stmts since
this is now possible after removing the only use which was chaining
of vector stmts via STMT_VINFO_RELATED_STMT.

This also removes all stmt_vec_info allocations done for vector
stmts, the remaining ones are for stmts in the scalar IL and for
patterns which are not part of the IL.  Thus after this the stmt
UIDs inside a basic-block are suitable for dominance checking
if you ignore (or lazy-fill) UIDs of zero of the vector stmts
inserted during transform.  This property is ensured by a new
flag set when pattern analysis is complete.

2020-06-10  Richard Biener  <rguenther@suse.de>

	* tree-vectorizer.h (_slp_tree::vec_stmts): Make it a vector
	of gimple * stmts.
	(_stmt_vec_info::vec_stmts): Likewise.
	(vec_info::stmt_vec_info_ro): New flag.
	(vect_finish_replace_stmt): Adjust declaration.
	(vect_finish_stmt_generation): Likewise.
	(vectorizable_induction): Likewise.
	(vect_transform_reduction): Likewise.
	(vectorizable_lc_phi): Likewise.
	* tree-vect-data-refs.c (vect_create_data_ref_ptr): Do not
	allocate stmt infos for increments.
	(vect_record_grouped_load_vectors): Adjust.
	* tree-vect-loop.c (vect_create_epilog_for_reduction): Likewise.
	(vectorize_fold_left_reduction): Likewise.
	(vect_transform_reduction): Likewise.
	(vect_transform_cycle_phi): Likewise.
	(vectorizable_lc_phi): Likewise.
	(vectorizable_induction): Likewise.
	(vectorizable_live_operation): Likewise.
	(vect_transform_loop): Likewise.
	* tree-vect-patterns.c (vect_pattern_recog): Set stmt_vec_info_ro.
	* tree-vect-slp.c (vect_get_slp_vect_def): Adjust.
	(vect_get_slp_defs): Likewise.
	(vect_transform_slp_perm_load): Likewise.
	(vect_schedule_slp_instance): Likewise.
	(vectorize_slp_instance_root_stmt): Likewise.
	* tree-vect-stmts.c (vect_get_vec_defs_for_operand): Likewise.
	(vect_finish_stmt_generation_1): Do not allocate a stmt info.
	(vect_finish_replace_stmt): Do not return anything.
	(vect_finish_stmt_generation): Likewise.
	(vect_build_gather_load_calls): Adjust.
	(vectorizable_bswap): Likewise.
	(vectorizable_call): Likewise.
	(vectorizable_simd_clone_call): Likewise.
	(vect_create_vectorized_demotion_stmts): Likewise.
	(vectorizable_conversion): Likewise.
	(vectorizable_assignment): Likewise.
	(vectorizable_shift): Likewise.
	(vectorizable_operation): Likewise.
	(vectorizable_scan_store): Likewise.
	(vectorizable_store): Likewise.
	(vectorizable_load): Likewise.
	(vectorizable_condition): Likewise.
	(vectorizable_comparison): Likewise.
	(vect_transform_stmt): Likewise.
	* tree-vectorizer.c (vec_info::vec_info): Initialize
	stmt_vec_info_ro.
	(vec_info::replace_stmt): Copy over stmt UID rather than
	unsetting/setting a stmt info allocating a new UID.
	(vec_info::set_vinfo_for_stmt): Assert !stmt_vec_info_ro.