bug#50985: Merging gnulib for Emacs 28.1?

[Stefan Kangas]

X-Debbugs-CC: eggert@cs.ucla.edu

AFAICT, the last merge of Gnulib was in January:

    commit 7c9841b8428edfbc369eccf54788b668d4b27328
    Author: Paul Eggert <eggert@cs.ucla.edu>
    Date:   Sat Jan 23 11:35:44 2021 -0800

        Update from Gnulib by running admin/merge-gnulib

Running admin/merge-gnulib also gives these new files:

     lib/realloc.c
     m4/malloc.m4
     m4/realloc.m4
     m4/year2038.m4

Should we merge the latest changes from Gnulib into the emacs-28
branch?  There seems to have been a fair bit of portability bug fixes,
but I don't know how important they are:

    https://git.savannah.gnu.org/cgit/gnulib.git/log/