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
return menuModel.getChildren().size();
		}
		int idx = 0;
		int size = menuModel.getChildren().size();
		while (idx < size) {
			if (id.equals(menuModel.getChildren().get(idx).getElementId())) {
				if ("after".equals(modifier)) {
					idx++;
				}
				return idx;
			}
			idx++;
		}
		return id.equals("additions") ? menuModel.getChildren().size() : -1;
	}
	private void removeMenuContributions(final MMenu menuModel,
			final ArrayList<MMenuElement> menuContributionsToRemove) {
		for (MMenuElement item : menuContributionsToRemove) {
			if (DEBUG) {
				trace("removeMenuContributions " + item,
						(Widget) menuModel.getWidget(), menuModel);
			}
			menuModel.getChildren().remove(item);
		}
	}
	private void handlerRenderedMenu(final Event event, final Menu menu,
			final MRenderedMenu menuModel) {
		
		switch (event.type) {
		case SWT.Show: