match.pd: Fix .PARITY(~x) simplification [PR126471]

The parity(~X) simpliciation to parity(X) is incorrect for types with
odd element precision, in that case parity(~X) is equivalent to
parity(X) ^ 1.
The following patch fixes this.

2026-07-30  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/126471
	* match.pd (parity(~X) is parity(X)): Only optimize this way
	if element_precision is even, otherwise optimize into parity(X) ^ 1.

	* gcc.dg/bitint-139.c: New test.

Reviewed-by: Andrea Pinski <andrew.pinski@oss.qualcomm.com>