[llvm] [BOLT][AArch64] Handle OpNegateRAState to enable optimizing binaries with pac-ret hardening (PR #120064)

[Paschalis Mpeis via llvm-commits]

paschalis-mpeis wrote:

> One think to keep in mind here: the BTI fixup is missing..
> ..Ideally, the -update-branch-protection={yes|strict|no} option would be used once BTI fixups are in place.

Sounds good. Yeap, we currently can't handle BTI.
Maybe something like: `-update-branch-protection={all|<list>|strict|no}` could do, where `<list>` can be comma-separated features: `pac,bti`

https://github.com/llvm/llvm-project/pull/120064