Go-to-definition on `return` statements should jump to the containing function declaration

```ts
function foo() {
    return /*END*/() => {
        /*START*/return 10;
    }
}
```

Go to definition on `START` should jump you up to the containing function.

It should be resilient to questionable placements of `return` and do nothing, as in the following cases.

```ts
/*a*/return;


function foo() {
    class Foo {
       static { /*b*/return; }
    }
}
```
