[clang] [libc] [llvm] [AMDGPU] Implement variadic functions by IR lowering (PR #93362)

[Joseph Huber via cfe-commits]

https://github.com/jhuber6 commented:

Overall I think this is good. Address the existing comments and I think we should be able to land it. Potentially we should be able to check for the existence of `va_start` in the module to early-exit like you said, which will keep functional changes to a minimum.

FWIW if you use `clangd` with `clang-tidy` it should let you automatically fix the LLVM style issues.

https://github.com/llvm/llvm-project/pull/93362