[llvm] [BOLT] Add CustomOffset flag for optimizing kernel (PR #98153)

[Davide Italiano via llvm-commits]

https://github.com/dcci requested changes to this pull request.

I don't think BOLT should be responsible for doing this. We want to have the input for BOLT to be canonicalized.

https://github.com/llvm/llvm-project/pull/98153