title: iOS 11UICollectionView scroll to top gets stuck with large titles
body: <p>The title is a mouthful, but here is what is happening. In iOS 11 when you have a navigation bar with large titles then you scroll down a ways and tap the status bar it will scroll to the top. When it scrolls to the top it gets stuck scrolling <em>past</em> the top. </p>
  
  <p>It looks super messed up, here is an example after it scrolled to the top. It scrolled so far it started pulling the refresh control! <a href="https://i.stack.imgur.com/BiX0y.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/BiX0y.png" alt="scrolled too far"></a></p>
  
  <p>Has anyone seen this and been able to fix it? Mail has a large title and doesn't have the problem, though it is likely not a <code>UICollectionView</code></p>
  
  <p>Here is a gif of it happening:
  <a href="https://i.stack.imgur.com/cBu8v.gif" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/cBu8v.gif" alt="enter image description here"></a></p>
  
  <p>As far as code goes it is as simple as I can make it:</p>
  
  <pre><code>extension ViewController: UICollectionViewDataSource {
      public func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -&gt; Int {
          return 100
      }
  
      public func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -&gt; UICollectionViewCell {
          let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "fakeCell", for: indexPath) as? UICollectionViewCell
          cell?.backgroundColor = [UIColor.black, .blue, .red, .green, .yellow][indexPath.row % 5]
          return cell!
      }
  
  }
  </code></pre>