bug#37563: 27.0.50; fit-frame-to-buffer does not account for line-spacing

[martin rudalics]

> I surely find the complexity of all this code jarring, so I have to
> restrict myself to looking at a single issue; and here, it's clearly
> fixing a bug, using the char height is simply wrong, IMO.

Agreed.  But if I change 'fit-frame-to-buffer', then, for consistency,
I have to at least change 'fit-window-to-buffer' too.

> +          (setq height (* (/ (+ height line-height -1) line-height)
> +                          line-height)))
[...]
> And then char-height can be dropped.

Right.

Thanks, martin