[llvm] [PAC][IR][AArch64] Add "ptrauth(...)" Constant to represent signed pointers. (PR #85738)

[Anton Korobeynikov via llvm-commits]

asl wrote:

> Well, no, but those are both used pretty infrequently. Actually, I forgot they already existed...

Yeah. So I hope there is already some sufficient coverage these days for these custom constants. They might be used infrequently, yes, but still I'd expect corner cases were found.

In any case, ptrauth is an opt-in option from the frontend perspective. So, we'd certainly run bunch of tests when there will be end-to-end support to catch something missed / not-covered here. Just my 2c.

https://github.com/llvm/llvm-project/pull/85738