title: Label's height behaving strangely when put inside UIView in a stack view
body: <p>I have a collection view cell. Inside this cell, I have a stack view with two labels. One is static height and one is dynamic height.</p>
  <p>If my hierarchy is as follows:</p>
  <pre><code>- Stack view (distribution = fill)
      - Label (vertical hugging = 250)
      - Label (vertical hugging = 249)
  </code></pre>
  <p>It sets the height fine for each cell:</p>
  <p><a href="https://i.stack.imgur.com/NDXD6.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/NDXD6.png" alt="enter image description here" /></a></p>
  <p><a href="https://i.stack.imgur.com/WaPiH.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/WaPiH.png" alt="enter image description here" /></a></p>
  <p>But when I place the label inside a UIView:</p>
  <pre><code>- Stack view (distribution = fill)
      - Label (vertical hugging = 250)
      - UIView (vertical hugging = 249)
          - Label (top, right, bottom, left constraints = superview)
  </code></pre>
  <p>It (most of the time) sets the height incorrectly:</p>
  <p>This appears as one line when it should appear as multiple:</p>
  <p><a href="https://i.stack.imgur.com/GtLkj.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/GtLkj.png" alt="enter image description here" /></a></p>
  <p>Adds weird padding above and below the label:</p>
  <p><a href="https://i.stack.imgur.com/FnODc.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/FnODc.png" alt="enter image description here" /></a></p>
  <p>What's going on here?</p>