[llvm] [NewPM] Don't preserve BlockFrequencyInfo in FunctionToLoopPassAdaptor (PR #157888)

[Luke Lau via llvm-commits]

lukel97 wrote:

> but this is doing something different, it's not preserving after all the loop passes run in the function -> loop adaptor. I think that should be fine compile-time-wise, it's equivalent to a function pass using and not preserving BFI

Thanks, that matches my understanding too.

FWIW it looks like after LoopPredication was changed to not use BFI in https://reviews.llvm.org/D111668, SimpleLoopUnswitch is the last user of BFI in LoopStandardAnalysisResults. I wonder if it's possible to do something similar to LoopPredication to remove the dependency?

BranchProbabilityInfo also seems to be unused, I'll try and open a PR to remove it. 

https://github.com/llvm/llvm-project/pull/157888