[llvm] [NewPM][CodeGen][llc] Add NPM support (PR #70922)

[Arthur Eubanks via llvm-commits]

aeubanks wrote:

I'd like this to land before any of the other patches so all the other patches have proper testing (unless other patches are blocking this one)

Will try to find some time to review this

https://github.com/llvm/llvm-project/pull/70922