[llvm] [SafeStack] Don't move a scalable byval argument to the unsafe stack (PR #225067)

[Timur Baidusenov via llvm-commits]

bai-tim wrote:

Superseded by #226170, which landed: a scalable byval is now rejected by the verifier, so SafeStack can no longer see one. Closing.

https://github.com/llvm/llvm-project/pull/225067