[llvm] [NVPTX] Diagnose an unsupported alias instead of aborting the compiler (PR #222651)

[Ashutosh Kumar Singh via llvm-commits]

Ashutosh0x wrote:

Confirming I have read the LLVM AI Tool Use Policy, the Code-Review Policy and Practices, and the Developer Policy.

This change was written with AI assistance, noted in the "AI tool use" section of the PR description and with an `Assisted-by:` trailer on the commit. I have read and reviewed the whole patch and I am accountable for it.

I've also rebased onto current `main` (`659faef77`) and re-run `llvm/test/CodeGen/NVPTX` on that base: 587/587 pass, `git clang-format` clean.


https://github.com/llvm/llvm-project/pull/222651