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

[Gergely Bálint via llvm-commits]

bgergely0 wrote:

Force push:
- rebased to main
- squased some of the commits together: new additions are kept in separate commits, but their "review nits" and short bugfix commits are squashed onto the respective "feature commits"
- removed the `--allow-experimental-flag` for now. This caused several bugs, so it was best to remove it until I have a better solution.

Because of the bugs, current push is expected to be broken. I will push new additions (bugfixes) onto this.

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