Accessing localStorage fails

Here's a simple example:
```swift
let localStorage = JSObjectRef.global.localStorage.object!
print(localStorage.getItem!("hello"))
_ = localStorage.setItem!("hello", "world")
print(localStorage.getItem!("hello"))
```
Prints `null` then `.string("world")` as expected.

However, if you refresh the site after the value is set, it crashes with `Reflect.get called on non-object`.