test: derive repr for enum

Author: Bogay

test/src/test_export_enum.rs

@@ -1,6 +1,8 @@
 use gdnative::prelude::*;
 
 #[derive(Debug, PartialEq, Clone, Copy, Export, ToVariant, FromVariant)]
+#[variant(enum = "repr")]
+#[repr(i32)]
 enum Dir {
     Up = 1,
     Down = -1,