fallBackToSpringForward() fails to make progress

From https://bugs.eclipse.org/541103:

Despite fixes in https://bugs.eclipse.org/539685 completion gets stuck in this example:
```java
import java.beans.JavaBean;

@JavaBean(data -> {
data.
})
public class Main {

}
```

Interestingly, the problem happens only after the class header has been parsed successfully (into a RecoveredType with the annotation incl. lambda present). We constantly go into RESTART, but after `this.scanner.ungetToken(nextToken);` we never get additional input.

I think this deserves a glance from the master of `fallBackToSpringForward()`: @srikanth-sankaran