[llvm] [AArch64][PAuth] Fix return-address auth for swifttailcc with FPDiff > 0 (PR #203340)

[Oskar Wirga via llvm-commits]

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

Thanks for these merging these changes! LGTM!

https://github.com/llvm/llvm-project/pull/203340