struct.c: hide internal objects
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51082 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
struct.c: hide internal objects
object, and members object does not need to be duped as it
should be frozen and hidden.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51082 b2dd03c8-39d4-4d8f-98ff-823fe69b080e