bug#31929: [PATCH] Install emacs-module.h (Bug#31929)

[Glenn Morris]

Eli Zaretskii wrote:

>> After the fact, I'm wondering if this should obey the EMACS_NAME
>> transformation? My initial feeling is, yes.
>
> I'm not sure.  If we edit the name, a given module couldn't be
> compiled against differently-named Emacs distributions, which I think
> is undesirable. 

I think it is what users of the --program-prefix|suffix|transform
configure options will probably expect to happen.
Ie if someone wants "emacs" installed as "emacs27", I think they want
"emacs27-module.h" as well.

> Lastly, we name the file explicitly in the documentation.

The documentation also names eg the "emacs" and "emacslient"
executables, which are rather more fundamental. The documentation does
not account for the --program-transform etc options anywhere, and I
don't think it should. It's a specialized feature, and people who use it
should be able to deal with the consequences.