Add DL_EXPORT() to all modules that could possibly be used
on BeOS or Windows.
diff --git a/Modules/zlibmodule.c b/Modules/zlibmodule.c
index fc892d0..3e4e23d 100644
--- a/Modules/zlibmodule.c
+++ b/Modules/zlibmodule.c
@@ -788,7 +788,7 @@
 "objects support decompress() and flush()."
 ;
 
-void
+DL_EXPORT(void)
 PyInit_zlib()
 {
         PyObject *m, *d, *ver;