Update gnulib

This updates gnulib to a relatively recent commit.  Most of this was
done by the gnulib import script; the only change I made was to
update-gnulib.sh.

Tested on x86-64 Fedora 34.  I also did a mingw cross build.

gnulib/import/free.c

@@ -1,33 +1,37 @@
 /* Make free() preserve errno.
 
-   Copyright (C) 2003, 2006, 2009-2021 Free Software Foundation, Inc.
+   Copyright (C) 2003, 2006, 2009-2022 Free Software Foundation, Inc.
 
-   This program is free software: you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 3 of the License, or
-   (at your option) any later version.
+   This file is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
 
-   This program is distributed in the hope that it will be useful,
+   This file is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-   GNU General Public License for more details.
+   GNU Lesser General Public License for more details.
 
-   You should have received a copy of the GNU General Public License
+   You should have received a copy of the GNU Lesser General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
 
 /* written by Paul Eggert */
 
 #include <config.h>
 
+/* Specification.  */
 #include <stdlib.h>
 
-#include <errno.h>
+/* A function definition is only needed if HAVE_FREE_POSIX is not defined.  */
+#if !HAVE_FREE_POSIX
+
+# include <errno.h>
 
 void
 rpl_free (void *p)
-#undef free
+# undef free
 {
-#if defined __GNUC__ && !defined __clang__
+# if defined __GNUC__ && !defined __clang__
   /* An invalid GCC optimization
      <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98396>
      would optimize away the assignments in the code below, when link-time
@@ -39,9 +43,11 @@ rpl_free (void *p)
   errno = 0;
   free (p);
   errno = err[errno == 0];
-#else
+# else
   int err = errno;
   free (p);
   errno = err;
-#endif
+# endif
 }
+
+#endif