title: Auto Layout not properly handling iPhone X notch
body: <p>I have implemented a pageViewIndicator to the top of my application using swift. I have constantly tested it on my personal iPhone, which has worked, but when using the iPhone X simulator, I have noticed that it disappears behind the notch, simply because I did not reference to place it within the safe area or the safe area is not properly configured yet. Here is the comparison:</p>
  
  <p><a href="https://i.stack.imgur.com/EkhfO.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/EkhfO.png" alt="pageController on iPhone 8"></a>
  <a href="https://i.stack.imgur.com/awtS8.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/awtS8.png" alt="pageController on iPhone X"></a></p>
  
  <p>It seems like an easy question, yet I currently have not found any proper support on how to handle this: the main suggestion is to adjust the safeAreaInsets, yet I do not understand how to apply this to the <code>AutoLayout</code> functionality. I have tried adding a topAnchor constraint to the pageController, yet would it even be possible editing this using basic arithmetic?</p>
  
  <pre><code>pageControl.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor).isActive = true
  </code></pre>