I think the parent was trying to say LLVM implements pointer provenance semantics in some form, as "these" semantics doesn't really make sense. As to what form LLVM implements... a weird mishmash of many semantics, with some optimizations that are contradictory with each other and some that don't make sense.

PNVI-ae-udi looks to be the one that compiler developers and the committee agree on, but we'll see if these efforts gain any more traction.