[llvm] Aarch64: Emit a minimal SEH prologue when needed (PR #158173)

[Saleem Abdulrasool via llvm-commits]

https://github.com/compnerd approved this pull request.

I think that we can be more specific in the comment, but that isn't as important. It specifically is when the tail call has an airty mismatch and the resumption needs additional stack space for additional arguments.

https://github.com/llvm/llvm-project/pull/158173