Bug 214137 [Markers] Unbound system filters should be bound to problems view.
In 3.3 we supported systemFilters which are not currently picked up by the problems view. We should pick these up for compatiblity.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/views/markers/CachedMarkerBuilder.java
return visibleFields;
	}
	/**
	 * Return whether or not the receiver has markers without scheduling
	 * anything if it doesn't.
	 * 
	 * @return boolean <code>true</code> if the markers have not been
	 *         calculated.
	 */
	boolean hasNoMarkers() {
		return currentMap == null;
	}
	/**
	 * Return whether or not the receiver is building.
	 * 
	 * @return boolean
	 */
	boolean isBuilding() {
		return building;
	}
	/**
	 * Return whether or not we are showing a hierarchy,.
	 * 
	 * @return <code>true</code> if a hierarchy is being shown.
	 */
	boolean isShowingHierarchy() {
		return categoryGroup != null;
	}
	/**
	 * Load the filters preference.