bug#52018: 28.0.60; Improve documentation for compilation-finish-functions

[Eli Zaretskii]

> From: Thibault Polge <thibault@thb.lt>
> Cc: 52018@debbugs.gnu.org
> Date: Sun, 21 Nov 2021 20:44:46 +0100
> 
> > Why do you think this addition is of such great importance to have it
> > spelled out in the doc string?
> 
> All the docstring currently states about that argument is that it's “a
> string describing how the process finished”, which requires users to
> determine its possible values through trial and error, or by digging
> into the code.

I'm asking why do you think they should care.  If they want the
process exit status, they can have it, can't they?