[PATCH] Port config.guess to strict POSIX.1-2024 c17

[Paul Eggert]

* config.guess (set_cc_for_build):
Try the c17 compiler, standardized in POSIX.1-2024.  See:
https://pubs.opengroup.org/onlinepubs/9799919799/utilities/c17.html
While we're at it, prefer c99 to c89.
---
 config.guess | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/config.guess b/config.guess
index f6d217a..86bed2a 100755
--- a/config.guess
+++ b/config.guess
@@ -4,7 +4,7 @@
 
 # shellcheck disable=SC2006,SC2268 # see below for rationale
 
-timestamp='2024-01-01'
+timestamp='2024-07-27'
 
 # This file is free software; you can redistribute it and/or modify it
 # under the terms of the GNU General Public License as published by
@@ -123,7 +123,7 @@ set_cc_for_build() {
     dummy=$tmp/dummy
     case ${CC_FOR_BUILD-},${HOST_CC-},${CC-} in
        ,,)    echo "int x;" > "$dummy.c"
-              for driver in cc gcc c89 c99 ; do
+              for driver in cc gcc c17 c99 c89 ; do
                   if ($driver -c -o "$dummy.o" "$dummy.c") >/dev/null 2>&1 ; 
then
                       CC_FOR_BUILD=$driver
                       break
-- 
2.45.2