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
for (MMenuElement element : menuModel.getChildren()) {
			renderer.createGui(element, menu);
		}
	}
	private void unrender(final MMenu menuModel) {
		if (DEBUG) {
			trace("unrender", (Widget) menuModel.getWidget(), menuModel);
		}
		for (MMenuElement element : menuModel.getChildren()) {
			renderer.removeGui(element);
		}
	}
	private void gatherMenuContributions(final MMenu menuModel,
			final String id, final ArrayList<MMenuContribution> toContribute,
			final ExpressionContext eContext, boolean includePopups) {
		for (MMenuContribution menuContribution : application
				.getMenuContributions()) {
			String parentID = menuContribution.getParentID();
			boolean popup = parentID.equals("popup")
					&& (menuModel instanceof MPopupMenu) && includePopups;
			boolean filtered = isFiltered(menuModel, menuContribution);
			if (filtered || (!popup && !parentID.equals(id))
					|| !menuContribution.isToBeRendered()) {
				continue;
			}
			if (isVisible(menuContribution, eContext)) {
				toContribute.add(menuContribution);
			}
		}
	}