tree-optimization/104582 - Simplify vectorizer cost API and fixes

tree-optimization/104582 - Simplify vectorizer cost API and fixes

This simplifies the vectorizer cost API by providing overloads
to add_stmt_cost and record_stmt_cost suitable for scalar stmt
and branch stmt costing which do not need information like
a vector type or alignment.  It also fixes two mistakes where
costs for versioning tests were recorded as vector stmt rather
than scalar stmt.

This is a first patch to simplify the actual fix for PR104582.

2022-02-18  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/104582
	* tree-vectorizer.h (add_stmt_cost): New overload.
	(record_stmt_cost): Likewise.
	* tree-vect-loop.cc (vect_compute_single_scalar_iteration_cost):
	Use add_stmt_costs.
	(vect_get_known_peeling_cost): Use new overloads.
	(vect_estimate_min_profitable_iters): Likewise.  Consistently
	use scalar_stmt for costing versioning checks.
	* tree-vect-stmts.cc (record_stmt_cost): New overload.