[llvm] [NVPTX] Promote non-standard integer global widths to .u{8,16,32,64} (PR #197135)

[via llvm-commits]

DingchenZhu wrote:

@Artem-B @AlexMaclean — first-time contributor here, would appreciate a review when convenient. Pure NVPTX AsmPrinter fix for #154337, with an i1 behaviour disclosure noted in the description. The two commits are logically separable and can be squashed at merge time per LLVM workflow.

https://github.com/llvm/llvm-project/pull/197135