Optimize ClearNonLiveReferences: collect dependent code only from maps that are embedded in optimize

src/heap/heap.h

Index: src/heap/heap.h
diff --git a/src/heap/heap.h b/src/heap/heap.h
index 071681076fc60b37a82b34be8ae3706e4ba4aa5a..4b6c63e0c9606be9ddeb9f86acc2ef4dfc14e19b 100644
--- a/src/heap/heap.h
+++ b/src/heap/heap.h
@@ -2149,6 +2149,11 @@ class Heap {
   // For keeping track of context disposals.
   int contexts_disposed_;
 
+  // The length of the retained_maps array at the time of context disposal.
+  // This separates maps in the retained_maps array that were created before
+  // and after context disposal.
+  int number_of_disposed_maps_;
+
   int global_ic_age_;
 
   int scan_on_scavenge_pages_;