[llvm] [AArch64][PAC] Protect the entire function if pac-ret+leaf is passed (PR #140895)

[Eli Friedman via llvm-commits]

efriedma-quic wrote:

I don't think it's a problem to reorder the DWARF here... but I'd prefer that we generate consistent DWARF for pac-ret vs. pac-ret+leaf, to avoid any future confusion.

https://github.com/llvm/llvm-project/pull/140895