[llvm] [BOLT] Gadget scanner: detect non-protected indirect calls (PR #131899)

[Kristof Beyls via llvm-commits]

https://github.com/kbeyls commented:

As written in one of the specific comments, I'm fine with either this PR or #133227 landing first, whatever is most convenient to @atrosinenko .

I don't think there's anything I'd still would want to see changed in the patch before merging.
I'm not fully sure if @jacobbramley still wanted to see some changes before merging this patch? 

https://github.com/llvm/llvm-project/pull/131899