This patch adds a `-z` option to js and test-js. When run in this mode,
garbage cells are never actually destroyed. We instead keep them around
in a special zombie state.
This allows us to validate that zombies don't get marked in future GC
scans (since there were not supposed to be any more references!) :^)
Cells get notified when they become a zombie (via did_become_zombie())
and this is used by WeakContainer cells to deregister themselves from
the heap.
Make this API take a Span<Cell*> instead of a Vector<Cell*>&.
This is behavior neutral, but stops the API looking like it wants to
do mutable things to the Vector.
This is so that we can reliably allocate them in a template function,
e.g. in ordinary_create_from_constructor():
global_object.heap().allocate<T>(
global_object, forward<Args>(args)..., *prototype);
The majority of objects already take the prototype as the last argument,
so I updated the ones that didn't.
