[llvm] [NVPTX] Add NewPM codegen pipeline (PR #215712)

[Artem Belevich via llvm-commits]

Artem-B wrote:

> Was this enabling the NewPM for opt?

IIRC, we were switching between old/new PM via clang flags, so I guess it was affecting both opt and llc related parts of the pipeline. It's been a while back, so I do not recall the details.

@alinas I vaguely recall that you were the go-to person for the new PM switchover. Is there anything we need to worry about transitioning to the new PM here?

https://github.com/llvm/llvm-project/pull/215712