[llvm-dev] [NewPM] Purpose of the 'opt' option '-enable-new-pm'

[Markus Lavin via llvm-dev]

> `-enable-new-pm` is purely for the new PM transition, ideally at some point it will disappear when all tests are using `-passes`. We'll have to do a mass update of the lit tests at some point after the new PM transition, probably when we start thinking about deprecating the legacy PM (at least for the optimization pipeline).

Makes sense.

> (Also unrelated IMO having a `-passes` flag instead of specifying each pass as its own flag is a lot cleaner)

FWIW, I agree.