Bug: Marks the wrong parameter

``` js
[1, 2, 3].forEach((n) => {}, this);
```

This is a one line JavaScript code.

It marks the second parameter as "index". But actually it should be "thisArg":

``` 
[1, 2, 3].forEach(callbackfn: (n) => {}, index: this);
```

It should be:

``` 
[1, 2, 3].forEach(callbackfn: (n) => {}, thisArg: this);
```