Crude way to fix a problem on AIX: #undef STAT before defining it.
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index f897d0a..1afba39 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -285,6 +285,7 @@
 #endif
 
 /* choose the appropriate stat and fstat functions and return structs */
+#undef STAT
 #ifdef MS_WIN64
 #	define STAT _stati64
 #	define FSTAT _fstati64