[llvm] [NVPTX] use untyped loads and stores where ever possible (PR #137698)

[Artem Belevich via llvm-commits]

https://github.com/Artem-B approved this pull request.

Nice. I think I can see where you're going and I like the direction. 
LGTM.

https://github.com/llvm/llvm-project/pull/137698