title: QML can't anchor to item in layout
body: <p>Observe this quick example:</p>
  
  <pre><code>import QtQuick 2.9
  import QtQuick.Controls 2.2
  import QtQuick.Layouts 1.2
  
  ApplicationWindow {
      visible: true
      width: 100
      height: 100
  
      Label {
          text: "foobar"
  
          anchors.bottom: row.top
          anchors.left: label1.right
      }
  
      RowLayout {
          id: row
          anchors.bottom: parent.bottom
          width: parent.width
  
          Label {
              id: label1
              text: "hello1"
              Layout.alignment: Qt.AlignLeft
          }
          Label {
              id: label2
              text: "hello2"
              Layout.alignment: Qt.AlignRight
          }
      }
  }
  </code></pre>
  
  <p>I have two items in row layout, and I want to anchor the third label to one of them. This is what i get:
  <a href="https://i.stack.imgur.com/2FmHJ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/2FmHJ.png" alt="foobad"></a></p>
  
  <p>I expect foobar to be more to the right, but it's not what I get.</p>
  
  <p>Also with this any margins I set to the label will be ignored too.</p>
  
  <p>I can anchor to window or to RowLayout and it would work nicely, but for some reason I can't anchor to items inside the layout. What's the reason and what's the appropriate solution for this?</p>