We don't need to perform inside layout of flex and grid formatting
contexts when one of their ancestors is undergoing intrinsic size
measurement. This is because the parent formatting context will have
already sized the flex/grid container, and thus inside layout is
completely redundant work.
We already have a check to skip the layout of descendants if the
available size is intrinsic, but this is not sufficient in nested
intrinsic layout cases, where the available size might be definite even
though we are in intrinsic layout mode.
This commit introduces proper handling of three intrinsic size keywords
when used for CSS heights:
- min-content
- max-content
- fit-content
This necessitated a few plumbing changes, since we can't resolve these
values without having access to containing block widths.
This fixes some visual glitches on https://www.supabase.com/ as well
as a number of WPT tests. It also improves the appearance of dialogs.
Resulting in a massive rename across almost everywhere! Alongside the
namespace change, we now have the following names:
* JS::NonnullGCPtr -> GC::Ref
* JS::GCPtr -> GC::Ptr
* JS::HeapFunction -> GC::Function
* JS::CellImpl -> GC::Cell
* JS::Handle -> GC::Root
compute_inset() was incorrectly retrieving the containing block size
because containing_block() is unaware of grid areas that form a
containing block for grid items but do not exist in the layout tree.
With this change, we explicitly pass the containing block into
compute_inset(), allowing it to correctly provide the containing block
sizes for grid items.
