[llvm] [BOLT][AArch64] Preserve external branches to non-function symbols (PR #227275)

[Alexandros Lamprineas via llvm-commits]

labrinea wrote:

@rafaelauler @adam-bzowski I am not sure we want this. Please take a look. Alternatively we may prefer to reject input where we branch outside of a function to a symbol that is not `STT_FUNC`.

https://github.com/llvm/llvm-project/pull/227275