Location is missing some exotic behaviors

[pshaughn]

WPT html/browsers/history/the-location-interface/ has various tests that the Location exotic object does things in its own way, as https://html.spec.whatwg.org/multipage/history.html#the-location-interface warns us it must. Some of these tests fail, such as the ones that try to set its prototype. I don't know how much of this is codegen's responsibility and how much is Location::new_inherited's responsibility.

[pshaughn]

servo/components/script/dom/bindings/proxyhandler.rs

Lines 117 to 120 in 8002c6b

	/// This implementation always handles the case of the ordinary
	/// `[[GetPrototypeOf]]` behavior. An alternative implementation will be
	/// necessary for the Location object.
	pub unsafe extern "C" fn get_prototype_if_ordinary(

WindowProxy has a special different get_prototype_if_ordinary to itself; Location must need one too.