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.swt/src/org/eclipse/e4/ui/workbench/swt/modeling/MenuServiceFilter.java
try {
			handleAboutToShow.invoke(manager);
		} catch (IllegalArgumentException e) {
			
			e.printStackTrace();
		} catch (IllegalAccessException e) {
			
			e.printStackTrace();
		} catch (InvocationTargetException e) {
			
			e.printStackTrace();
		}
		if (menuModel.getChildren().size() == 1
				&& menuModel.getChildren().get(0) instanceof MPopupMenu) {
			showPopup(event, menu, (MPopupMenu) menuModel.getChildren().get(0));
		} else {
			showMenu(event, menu, menuModel);
		}
		event.type = SWT.None;
		event.doit = false;
	}
	private void cleanUp(final Menu menu) {
		if (DEBUG) {
			trace("cleanUp", menu, null);
		}
		if (pendingCleanup.isEmpty()) {
			return;
		}
		Runnable cleanUp = pendingCleanup.remove(menu);
		if (cleanUp != null) {