[REGRESSION] nested layout not correctly polished on start

Culprit is commit 70120c931faa0c6139354c75fcf8d39b77ec3b4a, i.e. 5.14.1 is fine.

The code is similar to what I have attached. What happens is that for the component that contains the scrollbar, and any components used after it (i.e. YetAnotherControl) the subcontrols are at the top left corner, overlapping even the grey control Rectangle. When someone touches the splitter things are layout out properly. If there are multiple controls with ScrollViews then the "healing" does not affect all of them, i.e. I have to make them visible, touch the splitter, but afterwards things are fine. The items inside the scrollview seem to be irrelevant, I get the effect also for ScrollViews with empty models.

I increased the limit in QQuickLayout::invalidate() from 2 to 3, which seems to fix the issue for me.