ruby.c: fix command line encoding on cygwin
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@54720 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
ruby.c: fix command line encoding on cygwin
other than UTF-8. [ruby-dev:49519] [Bug #12184]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@54720 b2dd03c8-39d4-4d8f-98ff-823fe69b080e