Minor rearrangement for src/conf_post.h

* src/conf_post.h (config_opsysfile):
Move earlier, so that WINDOWSNT is available.
(alloca.h) [WINDOWSNT]: Don't include it on MS Windows.

src/ChangeLog

 2012-07-31  Glenn Morris  <rgm@gnu.org>
+	* conf_post.h (config_opsysfile): Move earlier, so that WINDOWSNT
+	is available.
+	(alloca.h) [WINDOWSNT]: Don't include it on MS Windows.
+
 	* process.h (NULL_DEVICE):
 	* emacs.c (SEPCHAR):
 	* editfns.c (USER_FULL_NAME): Let configure set them.

src/conf_post.h

@@ -27,11 +27,18 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
 /* Code: */
 
+/* Include any platform specific configuration file.  */
+#ifdef config_opsysfile
+# include config_opsysfile
+#endif
+
+#ifndef WINDOWSNT
 /* On AIX 3 this must be included before any other include file.  */
 #include <alloca.h>
 #if ! HAVE_ALLOCA
 # error "alloca not available on this machine"
 #endif
+#endif
 
 #ifdef SIGNAL_H_AHB
 #undef SIGNAL_H_AHB
@@ -107,11 +114,6 @@ char *_getpty();
 #endif
 #endif  /* USG5_4 */
 
-/* Include the os dependent file.  */
-#ifdef config_opsysfile
-# include config_opsysfile
-#endif
-
 /* Mac OS X / GNUstep need a bit more pure memory.  Of the existing knobs,
    SYSTEM_PURESIZE_EXTRA seems like the least likely to cause problems.  */
 #ifdef HAVE_NS