[llvm] [DAGCombiner] add fold (xor (smin(x, C), C)) and fold (xor (smax(x, C), C)) (PR #155141)

[guan jian via llvm-commits]

rez5427 wrote:

> These seem to be better generic alive2 checks - can you confirm? https://alive2.llvm.org/ce/z/gffoir

Confirmed. I should have done it like you did, sorry.

https://github.com/llvm/llvm-project/pull/155141