[llvm] [CodeGen][NPM] MachineScheduler: Inline constructors (PR #126220)

[Akshat Oke via llvm-commits]

optimisan wrote:

@nikic could you check with the tracker bot?

The current procedure to port passes to the NPM is to extract the logic out to an implementation class and create legacy and new (PM) passes that wrap over the implementation class. This introduces the Impl object construction and method call overheads for every pass.

Another approach would be to keep the legacy pass as-is and wrap the new pass over the legacy pass, which would keep the legacy path relatively free of the Impl reference.

https://github.com/llvm/llvm-project/pull/126220