JavaScript debugger can't evaluate expression evaluators

1. Open project qtdeclarative\examples\quick\demos\samegame\samegame.qmlproject from Qt5's repository.
2. Set a breakpoint at the first line of function startNewGame(gc, mode, map).
3. Run the project in debugger.
4. In the app click "1 Player".
   The breakpoint is being hit.
5. In "Locals and Expressions" view, right-click "this" and select "Add Expression Evaluator for 'this'" from the context menu.
   An expression evaluator for "this" will be added in the lower part of the "Locals and Expressions" view. Instead of a value, "unimplemented command 'evaluate'" is being displayed.

The "Locals and Expressions" view should display the values of expression evaluators correctly.