[llvm] [AArch64] Codegen for AArch64 Return Address Signing Hardening (PR #176187)

[Anatoly Trosinenko via llvm-commits]

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atrosinenko wrote:

Given the above assumption that MBBI points at `RET X30`, this looks like a no-op.

https://github.com/llvm/llvm-project/pull/176187