Rename produces double name in shortcut refinement syntax
``` ceylon
interface Sup {
    shared formal Anything f;
}
class Sub() satisfies Sup {
    f => 0;
}
```

If you Rename (Alt+Shift+R, at least on my system) `f` to, say, `g`, you get

``` ceylon
interface Sup {
    shared formal Anything g;
}
class Sub() satisfies Sup {
    gg => 0;
}
```

`Sub.f` got changed to `gg` rather than `g`.
