Add checks for memfd_create() and posix_fallocate() to the autotools build

(cherry picked from commit 59d4a39456)

configure

@@ -19749,6 +19749,18 @@ if test "x$ac_cv_func_poll" = xyes
 then :
   printf "%s\n" "#define HAVE_POLL 1" >>confdefs.h
 
+fi
+ac_fn_c_check_func "$LINENO" "memfd_create" "ac_cv_func_memfd_create"
+if test "x$ac_cv_func_memfd_create" = xyes
+then :
+  printf "%s\n" "#define HAVE_MEMFD_CREATE 1" >>confdefs.h
+
+fi
+ac_fn_c_check_func "$LINENO" "posix_fallocate" "ac_cv_func_posix_fallocate"
+if test "x$ac_cv_func_posix_fallocate" = xyes
+then :
+  printf "%s\n" "#define HAVE_POSIX_FALLOCATE 1" >>confdefs.h
+
 fi
 ac_fn_c_check_func "$LINENO" "_Exit" "ac_cv_func__Exit"
 if test "x$ac_cv_func__Exit" = xyes