Move @override processing to Tag class.

        :name => detect_name(:class, doc_map),

        :doc => detect_doc(docs),

        :enum => detect_enum(doc_map),

        :override => extract(doc_map, :override, :class),

      }, doc_map)

    end

  class Override < Tag

    def initialize

      @pattern = "override"

      @key = :override

      @ext_define_pattern = "override"

    end

    # @override nameOfOverride

    def parse(p)

      p.add_tag(:override)

      p.maybe_ident_chain(:class)

      p.maybe_ident_chain(:override)

      # 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[:class]

      unless p.current_tag[:override]

        p.remove_last_tag

      end

    end

    def process_doc(tags)

      tags[0][:override]

    end

    def parse_ext_define(cls, ast)

      cls[:override] = JsDuck::AstUtils.make_string(ast)

    end