AW: Cleaning up include file inconsistencies

[Dr. Matthias St. Pierre]

> > > That, to me, is much clearer than the "_int" suffix.
> >
> > This sounds like an excellent idea to me.
> 
> "Someone" should create a PR...

I wouldn't mind doing it alongside the other changes in #9274,
but I'd prefer my alternative proposal, which I just posted before.
That is, if you agree of course.

If you insist on doing it as a separate PR, I don't mind. But it does
not make sense to start on it before #9274 has been accepted and
merged.

Matthias