dir.c: match in UTF-8

* dir.c (push_glob): match in UTF-8 on Mac OS X.
  [ruby-dev:48213] [Bug #9825]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45904 b2dd03c8-39d4-4d8f-98ff-823fe69b080e