Fix GC mark leaks for `MRB_TT_BREAK`; fix #5168

src/gc.c

@@ -760,6 +760,14 @@ gc_mark_children(mrb_state *mrb, mrb_gc *gc, struct RBasic *obj)
     mrb_gc_mark_range(mrb, (struct RRange*)obj);
     break;
 
+  case MRB_TT_BREAK:
+    {
+      struct RBreak *brk = (struct RBreak*)obj;
+      mrb_gc_mark(mrb, (struct RBasic*)mrb_break_proc_get(brk));
+      mrb_gc_mark_value(mrb, mrb_break_value_get(brk));
+    }
+    break;
+
   default:
     break;
   }
@@ -1019,6 +1027,7 @@ gc_gray_counts(mrb_state *mrb, mrb_gc *gc, struct RBasic *obj)
 
   case MRB_TT_PROC:
   case MRB_TT_RANGE:
+  case MRB_TT_BREAK:
     children+=2;
     break;