Bug 39746 Move super class constructor combo up.
Move the combo selection for the super class constructors to be above the field treeviewer for the "Create constructor using fields" source action.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/actions/CreateNewConstructorAction.java
* Note: This constructor is for internal use only. Clients should not call this constructor.
	 */
	public CreateNewConstructorAction(CompilationUnitEditor editor) {
		this(editor.getEditorSite());
		fEditor= editor;
		setEnabled(checkEnabledEditor());
	}
	
	
	
	/* (non-Javadoc)
	 * Method declared on SelectionDispatchAction
	 */
	public void selectionChanged(IStructuredSelection selection) {
		try {
			setEnabled(canEnable(selection));
		} catch (JavaModelException e) {
			
			if (JavaModelUtil.filterNotPresentException(e))
				JavaPlugin.log(e);
			setEnabled(false);
		}
	}
	
	private boolean canEnable(IStructuredSelection selection) throws JavaModelException {
		if (getSelectedFields(selection) != null)
			return true;
		if ((selection.size() == 1) && (selection.getFirstElement() instanceof IType)) {
			IType type= (IType) selection.getFirstElement();
			return type.getCompilationUnit() != null && type.isClass();