Implement immutable prototype chains

src/objects-printer.cc

Index: src/objects-printer.cc
diff --git a/src/objects-printer.cc b/src/objects-printer.cc
index 464177b57c42866faf63a787fd7171d8a613efa2..1233e02ab5f659de310de4ed65b392c2c8fb74bb 100644
--- a/src/objects-printer.cc
+++ b/src/objects-printer.cc
@@ -1144,7 +1144,8 @@ void ObjectTemplateInfo::ObjectTemplateInfoPrint(std::ostream& os) {  // NOLINT
   os << "\n - property_list: " << Brief(property_list());
   os << "\n - property_accessors: " << Brief(property_accessors());
   os << "\n - constructor: " << Brief(constructor());
-  os << "\n - internal_field_count: " << Brief(internal_field_count());
+  os << "\n - internal_field_count: " << internal_field_count();
+  os << "\n - immutable_proto: " << (immutable_proto() ? "true" : "false");
   os << "\n";
 }