[llvm] [LangRef][IR] Add 3 way compare <=> integer intrinsics (PR #83227)

[Miguel Raz Guzmán Macedo via llvm-commits]

miguelraz wrote:

@nikic if we're fine with adding/correcting the unit tests failing for now, this should be good to merge.

https://github.com/llvm/llvm-project/pull/83227