compile_stag

# File lib/erb.rb, line 631
    def compile_stag(stag, out, scanner)
      case stag
      when PercentLine
        add_put_cmd(out, content) if content.size > 0
        self.content = ''
        out.push(stag.to_s)
        out.cr
      when :cr
        out.cr
      when '<%', '<%=', '<%#'
        scanner.stag = stag
        add_put_cmd(out, content) if content.size > 0
        self.content = ''
      when "\n"
        content << "\n"
        add_put_cmd(out, content)
        self.content = ''
      when '<%%'
        content << '<%'
      else
        content << stag
      end
    end