match.pd: Move (X & C) eqne (Y & C) -> -> (X ^ Y) & C eqne 0 opt to match.pd [PR94718]

match.pd: Move (X & C) eqne (Y & C) -> -> (X ^ Y) & C eqne 0 opt to match.pd [PR94718]

This patch moves this optimization from fold-const.c to match.pd where it
is actually much shorter to do and lets optimize even code not seen together
in a single expression in the source, as the first step towards fixing the
PR.

2020-05-04  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/94718
	* fold-const.c (fold_binary_loc): Move (X & C) eqne (Y & C)
	-> (X ^ Y) & C eqne 0 optimization to ...
	* match.pd ((X & C) op (Y & C) into (X ^ Y) & C op 0): ... here.

	* gcc.dg/tree-ssa/pr94718-1.c: New test.
	* gcc.dg/tree-ssa/pr94718-2.c: New test.