i386: Add GENERIC and GIMPLE folders of __builtin_ia32_{min,max}* [PR116738]

i386: Add GENERIC and GIMPLE folders of __builtin_ia32_{min,max}* [PR116738]

The following patch adds GENERIC and GIMPLE folders for various
x86 min/max builtins.
As discussed, these builtins have effectively x < y ? x : y
(or x > y ? x : y) behavior.
The GENERIC folding is done if all the (relevant) arguments are
constants (such as VECTOR_CST for vectors) and is done because
the GIMPLE folding can't easily handle masking, rounding and the
ss/sd cases (in a way that it would be pattern recognized back to the
corresponding instructions).  The GIMPLE folding is also done just
for TARGET_SSE4 or later when optimizing, otherwise it is apparently
not matched back.

2024-09-25  Jakub Jelinek  <jakub@redhat.com>

	PR target/116738
	* config/i386/i386.cc (ix86_fold_builtin): Handle
	IX86_BUILTIN_M{IN,AX}{S,P}{S,H,D}*.
	(ix86_gimple_fold_builtin): Handle IX86_BUILTIN_M{IN,AX}P{S,H,D}*.

	* gcc.target/i386/avx512f-pr116738-1.c: New test.
	* gcc.target/i386/avx512f-pr116738-2.c: New test.