[llvm] CodeGen][NewPM] Port MachineScheduler to NPM. (PR #125703)

[Christudasan Devadasan via llvm-commits]

cdevadas wrote:

> This causes a compile-time regression: https://llvm-compile-time-tracker.com/compare.php?from=1d8c8d5dd0b73ee4285ab03e5ffa9bcc62a4a4d1&to=5aa4979c47255770cac7b557f3e4a980d0131d69&stat=instructions:u

We can analyze it and see the root cause. Should we revert the patch immediately?
If a follow-up patch can avoid the regression, is it ok to wait for a day or two before reverting it?

https://github.com/llvm/llvm-project/pull/125703