Ruby

parse.y: refine message for gvar w/o identitirs

• parse.y (parse_gvar): separate message for gvar without
  non-space characters from message for invalid identitirs.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@50480 b2dd03c8-39d4-4d8f-98ff-823fe69b080e