window.location is not supposed to be a read-only property

In [lib.dom.d.ts L13157](https://github.com/Microsoft/TypeScript/blob/master/lib/lib.dom.d.ts#L13157) window.location is set as a read-only property but it can also be used to redirect a user by changing the value of it.

For example:

```js
window.location = "/";
```

Error: 
```
[ts] Cannot assign to 'location' because it is a constant or a read-only property.
```