[Regr:5->6] Size bindings can be invalidated when anchors are set

import QtQuick 2.15

Item {
    id: plasmoid
    width: 300
    height: 300
    property int location: 0

    TapHandler {
        onTapped: if (plasmoid.location === 3) {
            plasmoid.location = 0;
        } else {
            plasmoid.location += 1;
        }
    }

    Rectangle {
        anchors {
            top: plasmoid.location === 0 ? undefined : parent.top
            left: plasmoid.location === 1 ? undefined : parent.left
            right: plasmoid.location === 2 ? undefined : parent.right
            bottom: plasmoid.location === 3 ? undefined : parent.bottom
        }
        height: (plasmoid.location === 3 || plasmoid.location === 0) ? 1 : undefined
        width: (plasmoid.location === 2 || plasmoid.location === 1) ? 1 : undefined
        z: 999 /* Draw the line on top of the applet */
        color: "red"
    }
}