[RFC] Increase libstdc++ line length to 100(?) columns

[Florian Weimer]

* Allan Sandfeld Jensen:

> If you _do_ change it. I would suggest changing it to 120, which is next 
> common step for a lot of C++ projects.

120 can be problematic for a full HD screen in portrait mode.  Nine
pixels per character is not a lot (it's what VGA used), and you can't
have any window decoration.  With a good font and screen, it's doable.
But if the screen isn't quite sharp, then I think you wouldn't be able
to use portrait mode anymore.