Bug 316298 [Compatibility] Support o.e.ui.menus visibleWhen
We need support in MCoreExpression for entire expressions created by the WorkbenchMenuService. They don't often use ReferenceExpressions to core expression definitions. PW
bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/ui/workbench/renderers/swt/MenuItemRenderer.java
}
		}
	};
	@PostConstruct
	public void init() {
		eventBroker.subscribe(UIEvents.buildTopic(UIEvents.UILabel.TOPIC),
				itemUpdater);
		eventBroker.subscribe(UIEvents.buildTopic(UIEvents.Item.TOPIC,
				UIEvents.Item.SELECTED), selectionUpdater);
		eventBroker
				.subscribe(UIEvents.buildTopic(UIEvents.Item.TOPIC,
						UIEvents.Item.ENABLED), enabledUpdater);
	}
	@PreDestroy
	public void contextDisposed() {
		eventBroker.unsubscribe(itemUpdater);
		eventBroker.unsubscribe(selectionUpdater);
		eventBroker.unsubscribe(enabledUpdater);
	}
	protected void processVisible(MMenuItem item) {
		if (menuItemToExpression.get(item) != null) {
			return;
		}
		MCoreExpression exp = (MCoreExpression) item.getVisibleWhen();
		ReferenceExpression ref = new ReferenceExpression(
				exp.getCoreExpressionId());
		menuItemToExpression.put(item, ref);
		IEclipseContext itemContext = getContext(item);
		VisibleRAT rat = new VisibleRAT(item, ref, itemContext);
		menuItemToRAT.put(item, rat);