configure: Move AC_USE_SYSTEM_EXTENSIONS up

We don't want to get warnings from autoconf about
AC_USE_SYSTEM_EXTENSIONS coming after AC_COMPILE_IFELSE.

diff --git a/configure.ac b/configure.ac
index 31228ca54501ae03df64ce12c4d1ac798344ae9d..6b7ddbe927b0346ff25609b1075c1a086b5511ef 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -189,6 +189,9 @@ case $host in
     ;;
 esac
 
+# Define _GNU_SOURCE etc. where appropriate, e.g. for strptime() on glibc
+AC_USE_SYSTEM_EXTENSIONS
+
 dnl
 dnl Check for a working C++ compiler, but do not bail out, if none is found.
 dnl We use this for an automated test for C++ header correctness.
@@ -227,8 +230,6 @@ LT_INIT([disable-static win32-dll])
 # Create libtool early, because it's used in configure
 LT_OUTPUT
 
-# Define _GNU_SOURCE etc. where appropriate, e.g. for strptime() on glibc
-AC_USE_SYSTEM_EXTENSIONS
 # Make sure we use 64-bit versions of various file stuff.
 AC_SYS_LARGEFILE