...when `LengthOrAutoOrCalculated` holds calculated value. We were
incorrectly assuming that if contained value is not auto, then it must
be a length.
Fixes crashing on https://hollowknightsilksong.com/
Inline nodes in our layout tree have a position, so let's show it. By
centralizing the logic for this, block nodes now lose their redundant
'content-size' dump info which is already part of the box model dump.
