Include Python.h first which defines _XOPEN_SOURCE
which allows the file to compile and removes a warning about _XOPEN_SOURCE
being redefined (works on AIX 4.3 and 5.1 at least).
diff --git a/Python/dynload_aix.c b/Python/dynload_aix.c
index fd380ae..03ecc07 100644
--- a/Python/dynload_aix.c
+++ b/Python/dynload_aix.c
@@ -1,15 +1,15 @@
 
 /* Support for dynamic loading of extension modules */
 
+#include "Python.h"
+#include "importdl.h"
+
 #include <ctype.h>	/*  for isdigit()	  */
 #include <errno.h>	/*  for global errno      */
 #include <string.h>	/*  for strerror()        */
 #include <stdlib.h>	/*  for malloc(), free()  */
 #include <sys/ldr.h>
 
-#include "Python.h"
-#include "importdl.h"
-
 
 #ifdef AIX_GENUINE_CPLUSPLUS
 #include "/usr/lpp/xlC/include/load.h"