* gc.c (rb_objspace_reachable_objects_from_root): do major marking.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43719 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* gc.c (heap_is_swept_object): use heap_page::before_sweep flag.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43720 b2dd03c8-39d4-4d8f-98ff-823fe69b080e