Make Override class return tagdef hash.

    # @override nameOfOverride

    def parse(p)

      p.add_tag(:override)

      p.maybe_ident_chain(:override)

      if classname = p.hw.ident_chain

        {

          :tagname => :override,

          :override => classname,

        }

      else

        # When @override not followed by class name, ignore the tag.

        # That's because the current ext codebase has some methods

        # tagged with @override to denote they override something.

        # But that's not what @override is meant for in JSDuck.

      unless p.current_tag[:override]

        p.remove_last_tag

      end

      # Ensure #parse returns nothing

        nil

      end

    end

    def process_doc(tags)

      tags[0][:override]