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

[martin rudalics]

> The meaning of "line height" in the C code (and related lisp functions)
> seems to be "line, without line-spacing", for better or worse.  Having
> line height mean sth different in window.el will make the situation
> worse, I guess :)
>
> Maybe we should go for an ugly, but different name like
> "line-height-w-space" instead?

This ship has sailed with the advent of 'default-line-height' in
simple.el, more or less.

martin