Interaction with `export * from`

Even though we do not support `export defer * from`, we still need to make sure that `export defer` and `export * from` interact properly. Consider this example:
```js
export * from "x";

// x
export defer { foo } from "y";
export defer { default } from "z";
```

Is `y` loaded? (probably yes)
Is `z` loaded? (ideally no)