[llvm] [AArch64][PAC] Support BLRA* instructions in SLS Hardening pass (PR #98062)

[Anatoly Trosinenko via llvm-commits]

atrosinenko wrote:

The [CI failure](https://buildkite.com/llvm-project/github-pull-requests/builds/79096#01909394-0f3c-4136-90f4-87cd922e27e9) seems to be unrelated to this PR: the assertion `Inserting PHI after debug-records!` was triggered when compiling `libcxx`, but IIUC it is native libcxx built by a "Linux x64" builder (x86_64, I assume), so it should not be affected in any way.

The next PR #98063 seems to be affected by the same CI failure, so just rebasing onto current HEAD of the `main` branch (+dropping old PR number from the commit message).

https://github.com/llvm/llvm-project/pull/98062