Wasm exports are immediately available to TypeScript, even gc objects!
```
<script type="text/wast">
(module
(type $Box (struct (field $val (mut i32))))
(global $box (export "box") (ref $Box) (struct.new $Box (i32.const 42)))
)
</script>
<script type="text/typescript">
const greeting: string = "Hello from TypeScript and Wasm!";
console.log(greeting, box.val);
</script>
