Add DL_EXPORT() to all modules that could possibly be used
on BeOS or Windows.
diff --git a/Modules/gdbmmodule.c b/Modules/gdbmmodule.c
index ae716ac..0df7df2 100644
--- a/Modules/gdbmmodule.c
+++ b/Modules/gdbmmodule.c
@@ -514,7 +514,7 @@
 	{ 0, 0 },
 };
 
-void
+DL_EXPORT(void)
 initgdbm() {
 	PyObject *m, *d;