Object.prototype.toString(m) !== '[object Module]'

[Guy Bedford]

In the module system, the `Symbol.toStringTag` on the module namespace object should be resulting in the following holding true:

```
import * as m from './m.js';
Object.prototype.toString(m) === '[object Module]';
```

But the above is currently returning `[object Object]` instead.

This is a useful feature for detecting if a given object is a module namespace object, which will likely be necessary for interop use cases in future.

[Guy Bedford]

Apologies - this works fine with `Object.prototype.toString.call(m)`... I missed the `call` here in my test! It works fine :)

[Yusuke Suzuki]

Ah, OK :)
No problem. Thank you for trying!