bug#39529: 28.0.50; Metahelp does not contain help text

[Eli Zaretskii]

> Date: Sun, 09 Feb 2020 21:22:54 +0200
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: 39529@debbugs.gnu.org
> 
> > From: Federico Tedin <federicotedin@gmail.com>
> > Date: Sun, 09 Feb 2020 20:06:40 +0100
> > 
> > On Emacs 28.0.50 (5e7bead8ea), typing C-h C-h will display the
> > *Metahelp* buffer, but instead of containing the usual help information,
> > it will contain just the following:
> > 
> > Automatically break line at a previous space, in insertion of text.
> 
> It's related to dumping in some way, because in temacs this works as
> expected.

I suspect the sxhash changes on Jan 7.  This problem started happening
in that day's build.