Before this change, we were going through the chain of base classes for
each IDL interface object and having them set the prototype to their
prototype.
Instead of doing that, reorder things so that we set the right prototype
immediately in Foo::initialize(), and then don't bother in all the base
class overrides.
This knocks off a ~1% profile item on Speedometer 3.
This lets us move a few Host-related functions (like serialization and
checks for what the Host is) into Host instead of having them dotted
around the codebase.
For now, the interface is still very Variant-like, to avoid having to
change quite so much in one go.
A couple of reasons:
- Origin's Host (when in the tuple state) can't be null
- There's an "empty host" concept in the spec which is NOT the same as a
null Host, and that was confusing me.
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