bug#45012: 27.1.50; Emacs 27.1 release archive missing emacs-module.h

[Eli Zaretskii]

> From: Philipp Stephani <p.stephani2@gmail.com>
> Date: Wed, 02 Dec 2020 18:52:26 +0100
> 
> The release archive for Emacs 27.1 as distributed on ftp.gnu.org is
> missing the emacs-module.h header.

This happens because emacs-module.h was removed from make-dist, in
this commit:

  commit 1043cd30acffcc0b61da4a80dcf3f8a5ac459267
  Author:     Paul Eggert <eggert@cs.ucla.edu>
  AuthorDate: Sat Jun 8 14:08:05 2019 -0700
  Commit:     Paul Eggert <eggert@cs.ucla.edu>
  CommitDate: Sat Jun 8 14:42:10 2019 -0700

      Fix out-of-source make-dist problems

      Problem with jisx2131-filter reported by Phillip Lord in:
      https://lists.gnu.org/r/emacs-devel/2019-06/msg00147.html
      * admin/charsets/Makefile.in (SED_SCRIPT):
      Put it in $(srcdir), which is not necessarily the working directory.
      ($(SED_SCRIPT)): Rename from jisx2131-filter.  All uses changed.
      (clean): Do not remove SED_SCRIPT.
      (extraclean): Remove it here instead.
      * make-dist (possibly_non_vc_files): Remove src/emacs-module.h.
      Although it is portable and could be distributed in the tarball,
      it's too much hassle to do that, so let each builder make it.

Wasn't there some discussion about the problems with distributing it,
as it is not entirely portable?