git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_3@44337 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
sweeper free up a dest object if a marker is invoked immediately
following allocate a dest object in rb_obj_alloc().
[Backport #9206]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_3@44337 b2dd03c8-39d4-4d8f-98ff-823fe69b080e