[llvm-branch-commits] [WebAssembly] Introduce CodeGenPassBuilder (PR #208983)

[Aiden Grossman via llvm-branch-commits]

https://github.com/boomanaiden154 created https://github.com/llvm/llvm-project/pull/208983

This is the equivalent of TargetPassConfig for the NewPM. This currently
mirrors the existing TargetPassConfig as close as possible, but with
TODOs for passes that have not been ported to the NewPM.