[llvm] [BOLT]Identify indirect call (PR #123305)

[Paschalis Mpeis via llvm-commits]

https://github.com/paschalis-mpeis commented:

Thanks again @liusy58.

Adding a few more comments for case (1) until we get some updates on my previous concern.

Could you also restructure a bit your commit message, including the PR title to note that this is for 'indirect tail calls' specifically, adding also `[AArch64]` tag?

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Marking indirect branches as functions calls (incl. their possible targets) can be an interesting case for the ABI discussions (ARM-software/abi-aa/issues/297). 

https://github.com/llvm/llvm-project/pull/123305