[llvm] [AArch64][PAC] Lower auth/resign into checked sequence. (PR #79024)

[Ahmed Bougacha via llvm-commits]

ahmedbougacha wrote:

> Some time ago I uploaded a re-implemented version of `@llvm.ptrauth.auth` intrinsic lowering: #72502 (currently marked as draft due to lesser patches being factored out from it that are on review now). Is the original implementation planned for upstreaming?

Why yes indeed, all the changes in the upstreaming branch are intended to be upstreamed.

Can you describe the differences that necessitated a reimplementation?  (of auth as well as blend–I see that's already been merged.)

https://github.com/llvm/llvm-project/pull/79024