* admin/merge-gnulib (GNULIB_MODULES): Add memeq, streq and remove
stringeq, to adjust to a module splitup in Gnulib.
* lib/memeq.c, lib/streq.c, lib/strnul.c, m4/memeq.m4, m4/streq.m4:
New files.
* lib/string.c, m4/stringeq.m4: Remove.

* admin/merge-gnulib (GNULIB_MODULES): Add crypto/sha3-buffer.
* lib/sha3.c: New file, imported by running admin/merge-gnulib.
* lib/sha3.h: Likewise.
* m4/sha3.m4: Likewise.
* lib/gnulib.mk.in: Updated by admin/merge-gnulib.
* m4/gnulib-comp.m4: Likewise.
* src/fns.c: Include sha3.h
(Fsecure_hash_algorithms): Add Qsha3_224, Qsha3_256, Qsha3_384, and
Qsha3_512.
(secure_hash): Likewise.
(Fsecure_hash): List the SHA-3 algorithms in the docstring.
(syms_of_fns): Define Qsha3_224, Qsha3_256, Qsha3_384, and Qsha3_512.
* test/lisp/net/gnutls-tests.el (gnutls-tests-internal-macs-upcased):
Filter out the new SHA-3 algorithms since they are currently not
implemented in gnutls.
* test/src/fns-tests.el (test-secure-hash): Add test cases for the new
algorithms.
* doc/lispref/text.texi (Checksum/Hash): List the SHA-3 algorithms.
Mention that they are considered secure.
* etc/NEWS: Mention the new feature.

Problem reported by Basil L. Contovounesios (bug#80428#8).
* admin/merge-gnulib (GNULIB_MODULES): Add ‘attribute’.

Uses of <vla.h>’s macro VLA_ELEMS were removed some time ago.
* admin/merge-gnulib (GNULIB_MODULES): Remove vla.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.
* lib/vla.h: Remove.
* src/fns.c, src/lread.c: Do not include <vla.h>.

* lib/save-cwd.c: Propagate changes from Gnulib sibling.
This doesn’t affect behavior.