* gc.c (gc_mark_all): tweak mark order for little bit better scan.
* gc.c (rb_gc_mark): ditto.
* gc.c (rb_gc): ditto.
* enum.c (sort_by_i): slight performance boost.
* gc.c (gc_mark_rest): should call gc_mark_children(), not gc_mark().
* gc.c (rb_gc_mark): may cause infinite looop.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@1861 b2dd03c8-39d4-4d8f-98ff-823fe69b080e