There are several changes here:
1) Adds some MutableThis methods to Optional, Nullable, and dictionaries to
effectively allow doing a const_cast without knowing the actual type being
templated over. I needed this because I do not in fact know that type in
the relevant code. I'm open to suggestions for a better name for this
method.
2) Adds some operator& to RootedJSValue to make it look more like a JS::Value,
and in particular so I can JS_WrapValue the thing in it.
3) Adds a Slot() method to NonNullLazyRootedObject, just like NonNull has.
4) Adds an operator& to LazyRootedObject to make it look more like JSObject* so
I can JS_WrapObject the thing in it.
5) Implements the actual rewrapping of the arguments into the content compartment.
6) Fixes a small preexisting bug in which we didn't look at named constructors
in getTypesFromDescriptor (this was causing my tests to not compile).
7) Changes Xrays to not enter the content compartment when calling a WebIDL
constructor.
8) Adds some friend API to report things as not being functions.
7a5392b28d