[llvm] [BOLT][AArch64] Fixes assertion errors occurred when perf2bolt was executed (PR #83394)

[Ádám Kallai via llvm-commits]

kaadam wrote:

> Hi! Thanks for test changing. I'm approving this tmp patch since handling the functions with IndirectBranchType::UNKNOWN is still better than aborting on these cases.

Thanks @yota9!
I'm not allowed to submit the PR, @yota9, @paschalis-mpeis may I ask one of you to merge the PR, if the PR has met the criteria for merging?

https://github.com/llvm/llvm-project/pull/83394