Note that I restricted this to --useDefineForClassFields is true.
Nothing changes when it's off. I think this is the correct fix for a
patch release.

However, in principal there's nothing wrong with moving parameter
property initialisation after property declaration initialisation. It
would be Extremely Bad and Wrong to rely on this working:

```ts
class C {
  p = this.q // what is q?
  constructor(public q: number) { }
}
```

But today it does, and probably somebody relies on it without knowing.