match: Add support for convert `((signed)x) < 0` to `x >= (unsigned)SIGNED_TYPE_MIN...

match: Add support for convert `((signed)x) < 0` to `x >= (unsigned)SIGNED_TYPE_MIN` while detecting min/max [PR110068]

This copies the optimization which was done to fix PR 95699 to match detection of MIN/MAX
from minmax_replacement to match.
This is another step in getting rid of minmax_replacement in phiopt.  There are still a few
more min/max detections that needs to be handled before the removal. pr101024-1.c adds one
example of that but since the testcase currently passes I didn't xfail it.

pr110068-1.c adds a testcase which was not detected beforehand either.

Changes since v1:
* v2: Fix comment about how it is transformed.
      Use SIGNED_TYPE_MIN everywhere instead of mxing in SIGNED_TYPE_MAX too.

Bootstrapped and tested on x86_64-linux-gnu.

	PR tree-optimization/95699
	PR tree-optimization/101024
	PR tree-optimization/110068

gcc/ChangeLog:

	* match.pd (`(type1)x CMP CST1 ? (type2)x : CST2`): Treat
	`(signed)x </>= 0` as `x >=/< SIGNED_TYPE_MIN`

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/pr101024-1.c: New test.
	* gcc.dg/tree-ssa/pr110068-1.c: New test.

Signed-off-by: Andrew Pinski <andrew.pinski@oss.qualcomm.com>