match.pd: A ^ ((A ^ B) & -(C cmp D)) -> (C cmp D) ? B : A simplification [PR94786]

match.pd: A ^ ((A ^ B) & -(C cmp D)) -> (C cmp D) ? B : A simplification [PR94786]

We already have x - ((x - y) & -(z < w)) and
x + ((y - x) & -(z < w)) simplifications, this one adds
x ^ ((x ^ y) & -(z < w)) (not merged using for because of the
:c that can be present on bit_xor and can't on minus).

2020-05-08  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/94786
	* match.pd (A ^ ((A ^ B) & -(C cmp D)) -> (C cmp D) ? B : A): New
	simplification.

	* gcc.dg/tree-ssa/pr94786.c: New test.