chakra Inherit problem

###### Version

chakra-1.11.24.0, 1.13.0.0-beta

###### Test case

```js
var obj = {
hi() {
super[1] = 'hello';
}
};
obj.hi();

print(JSON.stringify(obj))

```

###### Execution steps

.ch Testcase.js

###### Output
```
{}
```

###### Expected result
{"1":"hello"}

###### Description

The correct output of the test case should be `{"1":"hello"}` while chakra yields `{}` . I think it might be an issue of chakra.