[llvm] [IR] Autoupgrade trivial VP intrinsics to their non-VP counterparts (PR #212490)

[Luke Lau via llvm-commits]

lukel97 wrote:

> This is great to see, thanks!
> 
> Are there any remaining places that emit trivial VP intrinsics? If so, would be good to migrate them as well and possible add a note that they intrinsics are deprecated and should no longer be used?

Nothing internally to LLVM uses trivial VP intrinsics last time I checked, we've already mopped up the last remaining users of them in SelectionDAG. The plan would be to just remove the intrinsics entirely and erase them from the LangRef. I'm not sure if there's much value in deprecating them if they're already autoupgraded.

The only target that would observe any end-to-end difference would be VE. We can just add a note in the release notes to suggest users to switch over to the VE target intrinsics. 

https://github.com/llvm/llvm-project/pull/212490