make_tmpname

# File lib/tmpdir.rb, line 108
    def make_tmpname((prefix, suffix), n)
      prefix = (String.try_convert(prefix) or
                raise ArgumentError, "unexpected prefix: #{prefix.inspect}")
      suffix &&= (String.try_convert(suffix) or
                  raise ArgumentError, "unexpected suffix: #{suffix.inspect}")
      t = Time.now.strftime("%Y%m%d")
      path = "#{prefix}#{t}-#{$$}-#{rand(0x100000000).to_s(36)}"
      path << "-#{n}" if n
      path << suffix if suffix
      path
    end