Make the following changes by hand, and run 'admin/merge-gnulib'.
* .gitignore: Add lib/malloc/*.gl.h.
* admin/merge-gnulib: Copy lib/af_alg.h and lib/save-cwd.h
directly from Gnulib, without worrying about Gnulib modules,
as these files are special cases.
(AVOIDED_MODULES): Remove malloc-posix.
* lib/malloc.c, lib/realloc.c, m4/malloc.m4, m4/realloc.m4:
* m4/year2038.m4: New files, copied from Gnulib.
* lib/malloca.c, lib/malloca.h:
* m4/close-stream.m4, m4/glibc21.m4, m4/malloca.m4:
Remove. These are either no longer present in Gnulib, or are no
longer needed by modules that Emacs uses.
* oldXMenu/AddPane.c, oldXmenu/Addsel.c: Include XmenuInt.h first;
needed for new Gnulib.
* src/xmenu.c: Call emacs_abort, not abort.
This incorporates:
2020-03-28 Use module 'filename' instead of module 'dosname'
2020-03-28 dosname: Redirect to 'filename'
* lib/at-func.c, lib/canonicalize-lgpl.c, lib/dosname.h:
Copy from Gnulib.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.
* lib/filename.h: New file, copied from Gnulib.