bug#36357: Wrong Ghostscript program name on MS Win

[Eli Zaretskii]

> From: Sebastian Urban <mrsebastianurban@gmail.com>
> Date: Mon, 24 Jun 2019 18:04:41 +0200
> 
> Variable 'doc-view-ghostscript-program' has value - 'gs' - which is OK
> for Unix and VMS, but NOT OK for MS Windows.  It should be 'gswin32c'.
> For details look at the table in "How to Use Ghostscript", chapter
> "2.1 Help at the command line: gs -h".
> 
> Perhaps it should be done as list of choice, like in case of
> 'tex-dvi-view-command'?
> 
> Or as S. Monnier wrote: "(...) the default could simply
> (executable-find "gs") and (executable-find "gswin32c") and use
> whichever was found (...)".
> 
> Also the same table says 'gsos2' for OS/2 systems.

Tassilo, any objections to such a change?  It sounds TRT to me, but I
don't use these features, and don't have Ghostscript installed.

Thanks.