Bug 189490 [CommonNavigator] Go To->Resource won't enable
I0524 1. Open the Project Explorer in the Resource perspective 2. Create a vanilla project P 3. Create a folder F 4. Create a file resource R Open the Navigate->Go To file. "Resource..." will remain disabled.
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/navigator/CommonNavigator.java
* <p>
	 * Select Filters. Provides access to the "Select Filters" dialog that
	 * allows users to enable/disable filters and also the Content Extension
	 * activations.
	 * </p>
	 * </ul>
	 * 
	 * @return The Action Group to be associated with the Common Navigator View
	 *         Part.
	 */
	protected ActionGroup createCommonActionGroup() {
		return new CommonNavigatorActionGroup(this, commonViewer, getLinkHelperService());
	}
	/**
	 * @return The initial input for the viewer. Defaults to
	 *         getSite().getPage().getInput()
	 */
	protected IAdaptable getInitialInput() {
		return getSite().getPage().getInput();
	}
	/**
	 * <p>
	 * Updates the title text and title tool tip. Called whenever the input of
	 * the viewer changes.
	 * </p>
	 */
	protected void updateTitle() {
		if (commonViewer == null) {
			return;
		}