Work around a recent regression in C99 compatibility in autoconf.
The configure script was generated with an autoconf prerelease,
and the issue has been fixed upstream with this commit:

commit bf5a75953b6d504f0405b1ca33b039b8dd39eef4
Author: Zack Weinberg <zackw@panix.com>
Date:   Thu Nov 10 12:05:30 2022 -0500

    More fixes for compilers that reject K&R function definitions.

    This fixes all of the remaining failures exposed by running the
    testsuite with GCC 12 and
    CC='cc -Wimplicit-function-declaration -Wold-style-definition
           -Wimplicit-int -Werror'
    .

    * lib/autoconf/c.m4 (_AC_C_C89_TEST_GLOBALS): Don’t use K&R function
      definitions.
    * lib/autoconf/specific.m4 (AC_SYS_RESTARTABLE_SYSCALLS): Likewise.
      (AC_FUNC_MKTIME): Declare functions taking no arguments as ‘fn (void)’
      not ‘fn ()’.
    * lib/autoconf/c.m4 (_AC_C_C99_TEST_GLOBALS): Declare free().

diff --git a/configure b/configure
index 51bd10995a6f57e8..4bdd3ecca7d2c793 100755
--- a/configure
+++ b/configure
@@ -3954,9 +3954,7 @@ struct stat;
 /* Most of the following tests are stolen from RCS 5.7 src/conf.sh.  */
 struct buf { int x; };
 struct buf * (*rcsopen) (struct buf *, struct stat *, int);
-static char *e (p, i)
-     char **p;
-     int i;
+static char *e (char **p, int i)
 {
   return p[i];
 }
@@ -4007,6 +4005,7 @@ extern int puts (const char *);
 extern int printf (const char *, ...);
 extern int dprintf (int, const char *, ...);
 extern void *malloc (size_t);
+extern void free (void *);
 
 // Check varargs macros.  These examples are taken from C99 6.10.3.5.
 // dprintf is used instead of fprintf to avoid needing to declare