To allow implementing the DOM class hierarchy in JS bindings, this
patch adds an inherits() function that can be used to ask an Object
if it inherits from a specific C++ class (by name).
The necessary overrides are baked into each Object subclass by the
new JS_OBJECT macro, which works similarly to C_OBJECT in LibCore.
Thanks to @Dexesttp for suggesting this approach. :^)
This is a very barebones implementation of appendChild() that doesn't
take any of the idiosyncratic DOM behaviors into account yet.
Also teach the wrapper generator how to turn an Interpreter argument
into a Node&.
Instead of only checking the class_name(), we now generate an is_foo()
virtual in the wrapper generator. (It's currently something we override
on Bindings::Wrapper, which is not really scalable.)
Longer term we'll need to think up something smarter for verifying that
one wrapper "is" another type of wrapper.
This patch introduces a hackish but functional IDL parser and uses it
to generate the JS bindings for Node and Document.
We'll see how far this simple parser takes us. The important thing
right now is generating code, not being a perfect IDL parser. :^)
