bug#65340: further build failure on Android (Termux)

[Bruno Haible]

Gregory Heytings wrote:
> > Also, prior to the last several commits, building master under such an 
> > environment was impossible.
> 
> Not "impossible".  It required patches, such as those provided by the 
> Termux team

As long as such patches are not upstream,
  - It takes a while to find these downstream patches. They are at
    https://github.com/termux/termux-packages/tree/master/packages/emacs
    but this wasn't clear to me from the beginning.
  - It is an inconvenience to reapply such downstream patches each time
    you want to build a new snapshot from upstream.
That's why I opened this ticket, to make sure that the easiest possible
Emacs configuration actually builds out-of-the-box on Termux.

If you want to upstream the remaining 12-14 downstream patches, feel free
to open a new ticket.

Bruno