The existing implementation, which is used by Node::hit_test() and
sub-classes, does not include stacking contexts which prevents hit
testing from returning elements contained by those stacking contexts
in some situations.
This is quite rough and definitely not optimal. The stacking contexts
are not retrieved in the correct order. They should be sorted by
z-index then tree order.
This change makes DuckDuckGo technically usable with all the absolute
and relative positioning they use.
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