[llvm] [BOLT][AArch64] Do not crash on authenticated branch instructions (PR #129898)

[Alexey Moksyakov via llvm-commits]

yavtuk wrote:

> > One more point from my side, jump tables for aarch64 can be implemented over br & blr instructions. We should also include the checking for indirect call instructions
> > case AArch64::BLRAA:
> > case AArch64::BLRAB:
> > case AArch64::BLRAAZ:
> > case AArch64::BLRABZ:
> 
> @yavtuk Could you clarify this? If I understand the existing `analyzeIndirectBranchFragment` function correctly, it only matches the sequences ending in `br $xN` where `$xN` contains a sum of some base address and an addend, so I doubt authenticated branch instruction can be used instead of a plain `AArch64::BR` as the last instruction.

Current implementation for aarch64 supports only BR as indirect instruction for Jump tables, but I am working on the jump tables functionality right now, and I see a lot of JT with BLR instruction. If you are going to use BLRAA or other instructions it's worth to add checking for them as well

https://github.com/llvm/llvm-project/pull/129898