parser adds `$missing$` with wrong start position

As a follow-up from https://github.com/eclipse-jdt/eclipse.jdt.core/issues/3156:

For:

```
@Value(spring.) private String value1;
```

The fix for #3156 works, the `spring.` stay within the AST and a `SimpleName` node is added for the `$missing$` part behind the `.`. But the start position of the `$missing$` node is the same as the start position for the `QualifiedNode` and the same for the `SimpleNode` for `spring`.

I think the start position for the `$missing$` node should be right after the `.`.

(using `org.eclipse.jdt.core` 3.40.0)

(FYI: @mickaelistria and @stephan-herrmann)