[InstCombine] Fold minmax intrinsic using KnownBits information (#76242)

This patch tries to fold minmax intrinsic by using
`computeConstantRangeIncludingKnownBits`.
Fixes regression in
[_karatsuba_rec:cpython/Modules/_decimal/libmpdec/mpdecimal.c](https://github.com/python/cpython/blob/c31943af16f885c8cf5d5a690c25c366afdb2862/Modules/_decimal/libmpdec/mpdecimal.c#L5460-L5462),
which was introduced by #71396.
See also
https://github.com/dtcxzyw/llvm-opt-benchmark/issues/16#issuecomment-1865875756.

Alive2 for splat vectors with undef: https://alive2.llvm.org/ce/z/J8hKWd