pub(super) fn find_const(&mut self, id: IdentId) -> VMResult {
        match self.get_lexical_const(id)? {
            Some(v) => Ok(v),
            None => {
                let self_val = self.self_value();
                let class = self.globals.get_class(self_val);
                self.get_super_const(class, id)
            }
        }
    }
Search lexical class stack and then, search class inheritance chain for a constant `id`,
returning the value.
Returns error if the constant was not defined, or autoload failed.
ruruby/src/vm/executor/constants.rs