Make -fcpr-off, turning off CPR analysis in the demand analyser, a dynamic flag instead of a static flag.
Not much thought was given to how -fcpr-off works.
Currently its works by not *generating* CPR info.
But an alternative would be not to *exploit* CPR info, specifically during worker/wrapper generation. The advantage is that this is done in ONE place, namely mkWWcpr, in WwLib. That in turn is called only from mkWwBodies which already gets DynFlags. Easy!
So that would mean that CPR analysis still happens, but GHC generates no w/w split.
I think this would be a better plan. OK?