[llvm] [NVPTX] Add support for calling aliases (PR #81170)

[Alex MacLean via llvm-commits]

AlexMaclean wrote:

> CI says the `alias-errors.ll` test is failing now, probably something minor.

Oops, fixed! The Linux build is now passing and the Windows issue looks unrelated. 

https://github.com/llvm/llvm-project/pull/81170