tree-vect-patterns: Don't create over widening patterns for stmts used in reductions...

tree-vect-patterns: Don't create over widening patterns for stmts used in reductions [PR98848]

As discussed in the PR, the reduction code isn't able to cope with type
promotions/demotions in the reduction computation, so if we recognize an
over-widening pattern that has vect_reduction_def type, we most likely make
it non-vectorizable.

2021-02-02  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/98848
	* tree-vect-patterns.c (vect_recog_over_widening_pattern): Punt if
	STMT_VINFO_DEF_TYPE (last_stmt_info) is vect_reduction_def.

	* gcc.dg/vect/pr98848.c: New test.
	* gcc.dg/vect/pr92205.c: Remove xfail.