Run field initializers for new instance fields after a reload

runtime/vm/object_reload.cc

Index: runtime/vm/object_reload.cc
diff --git a/runtime/vm/object_reload.cc b/runtime/vm/object_reload.cc
index a1318b73b3a55e519c2f1f042be8a80dfa1803e9..b48c46e4f3becb3694bad160029d3a1e0e303b93 100644
--- a/runtime/vm/object_reload.cc
+++ b/runtime/vm/object_reload.cc
@@ -577,7 +577,8 @@ void Class::CheckReload(const Class& replacement,
 bool Class::RequiresInstanceMorphing(const Class& replacement) const {
   // Get the field maps for both classes. These field maps walk the class
   // hierarchy.
-  const Array& fields = Array::Handle(OffsetToFieldMap());
+  const Array& fields =
+      Array::Handle(OffsetToFieldMap(true /* original classes */));
   const Array& replacement_fields =
       Array::Handle(replacement.OffsetToFieldMap());