Support GADT?

[kevinresol]

Currently the following snippet will fail with:
src/tink/macro/Sisyphus.hx:81: characters 22-57 : Type not found : T

class Main {
	static function main() {
		trace(stringify(VInt(TInt8, 0)));
	}
	
	static function parse<T>(v:String) {
		return tink.Json.parse((v:CValue<T>));
	}
	static function stringify<T>(v:CValue<T>):String {
		return tink.Json.stringify(v);
	}
}

enum CType<T> {
	TUInt8:CType<Int>;
	TInt8:CType<Int>;
	TBool:CType<Bool>;
	TArray<V>(type:CType<V>, size:Int):CType<Array<V>>;
}

enum CValue<T> {
	VInt(type:CType<Int>, v:Int):CValue<Int>;
	VBool(v:Bool):CValue<Bool>;
	VArray<V>(type:CType<Array<V>>, v:Array<V>):CValue<Array<V>>;
}

Changing the signature of stringify to the following will make the error more epic:
static function stringify(v:CValue<Dynamic>):String