should mark child env from method (proc) objects

src/class.c

@@ -37,7 +37,7 @@ mrb_gc_mark_mt(mrb_state *mrb, struct RClass *c)
     if (kh_exist(h, k)){
       struct RProc *m = kh_value(h, k);
       if (m) {
-        paint_black(m);
+	mrb_gc_mark(mrb, (struct RBasic*)m);
       }
     }
   }

src/gc.c

@@ -345,8 +345,8 @@ gc_mark_children(mrb_state *mrb, struct RBasic *obj)
     break;
 
   case MRB_TT_CLASS:
-  case MRB_TT_SCLASS:
   case MRB_TT_MODULE:
+  case MRB_TT_SCLASS:
     {
       struct RClass *c = (struct RClass*)obj;