[llvm] [CodeGen][Pass] Add `TargetPassBuilder` (PR #137290)

[Stefan Gränitz via llvm-commits]

https://github.com/weliveindetail commented:

I agree that the interface should be as close as possible, but matching the interface doesn't mean we have to fake the classes. Let's look at an example that might make the code simpler. It might also help reviewers :)

https://github.com/llvm/llvm-project/pull/137290