[llvm] [AArch64][llvm] Some instructions should be `HINT` aliases (NFC) (PR #189926)

[via llvm-commits]

https://github.com/CarolineConcatto commented:

Can you add tests for:
hint #48, hint #49, hint #50, hint #51
I believe they are all stshh or shuh alias for hint.
We should also add hint tests for tsb and stshh
Similar to what was done in AArch64/armv8.5a-bti.s

https://github.com/llvm/llvm-project/pull/189926