[llvm] [BOLT][ICP] Propagate parent hash to newly inserted BBs for BAT (PR #171044)

[Amir Ayupov via llvm-commits]

aaupov wrote:

> rather than the entry of the BB([code](https://github.com/llvm/llvm-project/blob/llvmorg-22-init/bolt/lib/Passes/IndirectCallPromotion.cpp#L786-L791)). This seems to make it difficult in BoltAddressTranslation::write() to look up the original BB's hash/index using the inserted/copied BB's InputOffset.

Thanks for an update. Yes, my understanding was that new BBs inherit the input offset of the call, and we should be able to look up the containing block using `BRANCHENTRY` bit. Can you please elaborate why that doesn't work as intended?

https://github.com/llvm/llvm-project/pull/171044