[clang] [llvm] [PAC][Driver] Support `pauthtest` ABI for AArch64 Linux triples (PR #97237)

[Peter Smith via llvm-commits]

https://github.com/smithp35 commented:

Apologies for the delay in responding, been a bit backed up. I like the idea of pauthtest as it does give some leeway to change the signing schema.

I expect that with some work this could be made to work with bare-metal targets too, but I think it is best to stick with what has been tested so far.

Not had a chance to go through the tests in detail yet. Will aim to do that before the end of the week. 

https://github.com/llvm/llvm-project/pull/97237