[llvm] [BOLT] Move ADRRelaxationPass (PR #101371)

[Peter Waller via llvm-commits]

https://github.com/peterwaller-arm approved this pull request.

LGTM. I also wonder aloud if RemoveNops could be moved down, I don't see documentation suggesting what it is constrained by or if any other pass depends on it.

The other incidental observation is that passes mix `runOnFunctions() { if (!BC.isX86()) return; ... }` and having `if (arch) Manager.registerPass` in BinaryPassManager. Is there a rationale for each? I'm new here but from my perspective it would be easier to follow what's going on if the passes relevant to each architecture were clear from `runAllPasses()`. I'm not asking for this to be changed in now but do you concur that arch conditions could be hoisted out of the individual passes to make it clearer? Or is the status quo preferred?

https://github.com/llvm/llvm-project/pull/101371