Because we have stuff running in early globals, we stlil need a more elaborate version of this function that *does* take `fn_proto`. We also can't pull `scope` from the activation since this gets called to install traits.
This also makes it more difficult to accidentally build a class without calling it's initializer. Native/builtin class initializers should also be running now, too.
The only minor bit of jank is that we need a class initialized bit to flag classes we've already run, because our current lazy-init design for traits causes classes to be constructed twice. This is temporary and I intend to remove it along with lazy-init traits.
This also incurred a large number of ancillary changes, as it turns out nearly every native object is currently pulling a prototype and sticking it into an object. Right now, I have it instead pulling the constructor out of the prototype, but a future PR will also remove `system_prototypes` as well.
Other ancillary changes include:
* `Domain` now supports partial initialization to avoid an order-of-events issue. Accessing domain memory on a partially-initialized `Domain` will panic.
* `Domain` construction requires a full `activation` now, except for `global_scope` which needs to be initialized later with valid domain memory before user code runs.
* Pretty much every native object constructor now takes a proto/constr pair
* Trait lookup was rewritten to handle this. It's still buggy - seven tests don't work
* `TObject.construct` now actually does the full object construction dance. This allows `ClassObject` to implement the ES4 object construction pathway directly while `FunctionObject` maintains ES3 compatibility.
This is a tentative commit; there are still seven failing tests that I need to fix.