Fix:

error: type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int [-Wimplicit-int]
--- X11/configure.orig	2018-12-26 04:10:52.000000000 -0600
+++ X11/configure	2024-10-05 15:40:12.000000000 -0500
@@ -2943,7 +2943,7 @@
 cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
- main(int ac, char **av) { return 0; }
+ int main(int ac, char **av) { return 0; }
 _ACEOF
 rm -f conftest$ac_exeext
 if { (ac_try="$ac_link"