[clang] [llvm] [LLVM] Fix incorrect alignment on AMDGPU variadics (PR #96370)

[Joseph Huber via cfe-commits]

jhuber6 wrote:

> Incrementing by align is just a bug, of course the size is the real value. Whether we want to continue wasting space is another not-correctness discussion

Struct padding is pretty universal, AMDGPU seems the odd one out here. I wouldn't mind it so much if it didn't require me to know which vendor I was dealing with in the RPC implementation, but I suppose I could store that information somewhere if we want to use a compressed option and we know it works.

https://github.com/llvm/llvm-project/pull/96370