Reduce multiple_of_p uses

Reduce multiple_of_p uses

There are a few cases where we know we're dealing with (poly-)integer
constants, so remove the use of multiple_of_p in those cases to make
the PR100499 fix less impactful.

2022-01-24  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/100499
	* tree-cfg.cc (verify_gimple_assign_ternary): Use multiple_p
	on poly-ints instead of multiple_of_p.
	* tree-ssa.cc (maybe_rewrite_mem_ref_base): Likewise.
	(non_rewritable_mem_ref_base): Likewise.
	(non_rewritable_lvalue_p): Likewise.
	(execute_update_addresses_taken): Likewise.