Open Radar

 
Summary:
If a generic class in any way refers to its type from the implementation (e.g. by having a property of the same type or an array of elements of that type), the execution hangs on the creation of this type.

I discovered the issue when my OSS library failed to run after updating to beta 6: https://github.com/Thomvis/BrightFutures/tree/8e280e4554d39bf1eec39b5649cad44e00fb43b5. There is a minimum failing example below.

Steps to Reproduce:
Paste the following in a playground:

```
public class A<T> {
  var callbacks: A<T>?
}

let before = "before"
A<Int>()
let after = "after"
```

Expected Results:
I expect the playground to compile and execute completely.

Actual Results:
It does compile, but it seems to hang on the initialization of the A<T> type (`A<Int>()`). You can see this because the `after` constant is never initialized.

Version:
Xcode 6 beta 6

Notes:
This used to work perfectly fine in beta 5