Support weak heap references in the ConstantPool to support IsWeakObjectInOptimizedCode objects.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 787b6d82b47145688e92447ff2e57f24473ff5d7..1a8529eddaeb0818e275daee1ac80fa99063fb6e 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -9471,6 +9471,10 @@ void ConstantPoolArray::ConstantPoolIterateBody(ObjectVisitor* v) {
     int index = first_heap_ptr_index() + i;
     v->VisitPointer(RawFieldOfElementAt(index));
   }
+  for (int i = 0; i < count_of_weak_ptr_entries(); i++) {
+    int index = first_weak_ptr_index() + i;
+    v->VisitPointer(RawFieldOfElementAt(index));
+  }
 }