[llvm] [NVPTX] expand trunc v2i32->v2i16 (PR #161715)

[Princeton Ferro via llvm-commits]

https://github.com/Prince781 requested changes to this pull request.

LGTM but we also need to expand `any_extend`: https://godbolt.org/z/dfeeGEWqr

https://github.com/llvm/llvm-project/pull/161715