[llvm] [LV][EVL] Generate negative strided load/store for reversed load/store (PR #123608)

[Luke Lau via llvm-commits]

https://github.com/lukel97 commented:

Thanks, this is much preferred to having to lower experimental_vp_reverse in the risc-v backend. 

It looks like this also removes the only use of llvm.experimental.vp.reverse. Do we think we will need it for anything else in the EVL line of work? If not could we eventually end up removing it?

https://github.com/llvm/llvm-project/pull/123608