match.pd: Simplify (t * u) / (t * v) [PR112994]

match.pd: Simplify (t * u) / (t * v) [PR112994]

On top of the previously posted patch, this simplifies say (x * 16) / (x * 4)
into 4.  Unlike the previous pattern, this is something we didn't fold
previously on GENERIC, so I think it shouldn't be all wrapped with #if
GIMPLE.  The question whether there should be fold_overflow_warning for the
TYPE_OVERFLOW_UNDEFINED case remains.

2023-12-14  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/112994
	* match.pd ((t * u) / (t * v) -> (u / v)): New simplification.

	* gcc.dg/tree-ssa/pr112994-2.c: New test.