README.EXT{,.ja}: update ruby_options and ruby_run_node

* README.EXT{,.ja} (Appendix B): update contents of `ruby_options`
  and replace `ruby_run` with `ruby_run_node`.  based on the patch
  by Kaneko Yuichiro at [ruby-dev:48030] [Bug #9619].

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45312 b2dd03c8-39d4-4d8f-98ff-823fe69b080e