[llvm] [AArch64][PAC] Support BLRA* instructions in SLS Hardening pass (PR #97605)

[Anatoly Trosinenko via llvm-commits]

https://github.com/atrosinenko commented:

@kbeyls I updated the comments describing the changes made to the machine code, now I expect them to be up-to-date.

https://github.com/llvm/llvm-project/pull/97605