Update from gnulib

Update from gnulib

(cherry picked from commit 992cf3cb675e074079341cc54c3b16d37a8b9ca8)

This is a partial backport from master: it only includes the changes below.

* lib/mini-gmp.c (gmp_assert_nocarry): Avoid many Clang
unused-variable warnings when building with optimisation.
* lib/verify.h (_GL_HAVE__STATIC_ASSERT): Modify condition for using
_Static_assert to cope with older Apple builds of Clang exposing
misleading compiler version numbers.  See discussion starting at
https://lists.gnu.org/archive/html/emacs-devel/2022-04/msg00779.html