Add autoconf bits back to script per feedback in GH-21098

Author: NattyNarwhal

scripts/dev/update-libtool.sh scripts/dev/update-autotools.shscripts/dev/update-libtool.sh renamed to scripts/dev/update-autotools.sh

@@ -1,6 +1,6 @@
 #!/bin/sh
 #
-# Update the PHP libtool bits.
+# Update the PHP autotools (autoconf, libtool) bits.
 
 # Go to project root directory
 cd "$(CDPATH='' cd -- "$(dirname -- "$0")/../../" && pwd -P)" || exit
@@ -21,3 +21,18 @@ chmod +x build/ltmain.sh
 
 new_libtool_serial=$($grep -Po '(?<=^# serial )(\d*)(?=.*)' build/libtool.m4)
 echo "New libtool serial: $new_libtool_serial"
+
+# For config.*, GNU recommendation for updates is to download from Savannah
+# See: https://www.gnu.org/software/gettext/manual/html_node/config_002eguess.html
+
+update_file() {
+	old_ts=$("build/$1" -t)
+	echo "Old $1 timestamp: $old_ts"
+	url="https://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=$1;hb=HEAD"
+	wget -O "build/$1" "$url"
+	new_ts=$("build/$1" -t)
+	echo "New $1 timestamp: $new_ts"
+}
+
+update_file config.guess
+update_file config.sub