tree-optimization/92335 - Improve sinking heuristics for vectorization

The following delays sinking of loads within the same innermost
loop when it was unconditional before.  That's a not uncommon
issue preventing vectorization when masked loads are not available.

	PR tree-optimization/92335
	* tree-ssa-sink.cc (select_best_block): Before loop
	optimizations avoid sinking unconditional loads/stores
	in innermost loops to conditional executed places.

	* gcc.dg/tree-ssa/ssa-sink-10.c: Disable vectorizing.
	* gcc.dg/tree-ssa/predcom-9.c: Clone from ssa-sink-10.c,
	expect predictive commoning to happen instead of sinking.
	* gcc.dg/vect/pr65947-3.c: Ajdust.