match.pd: Guard 2 simplifications on integral TYPE_OVERFLOW_UNDEFINED [PR114090]

These 2 patterns are incorrect on floating point, or for -fwrapv, or
for -ftrapv, or the first one for unsigned types (the second one is
mathematically correct, but we ought to just fold that to 0 instead).

So, the following patch properly guards this.

I think we don't need && !TYPE_OVERFLOW_SANITIZED (type) because
in both simplifications there would be UB before and after on
signed integer minimum.

2024-02-26  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/114090
	* match.pd ((x >= 0 ? x : 0) + (x <= 0 ? -x : 0) -> abs x):
	Restrict pattern to ANY_INTEGRAL_TYPE_P and TYPE_OVERFLOW_UNDEFINED
	types.
	((x <= 0 ? -x : 0) -> max(-x, 0)): Likewise.

	* gcc.dg/pr114090.c: New test.