introduce eternal handles

src/heap.cc

Index: src/heap.cc
diff --git a/src/heap.cc b/src/heap.cc
index 5cd85445b4f169fc739dca8afbd8b1387733a5ac..785cfe79bc0a30d39b4047a5e2b672d2e018ed95 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -3223,9 +3223,6 @@ bool Heap::CreateInitialObjects() {
   }
   set_observed_symbol(Symbol::cast(obj));
 
-  set_i18n_template_one(the_hole_value());
-  set_i18n_template_two(the_hole_value());
-
   // Handling of script id generation is in Factory::NewScript.
   set_last_script_id(Smi::FromInt(v8::Script::kNoScriptId));
 
@@ -6613,6 +6610,10 @@ void Heap::IterateStrongRoots(ObjectVisitor* v, VisitMode mode) {
   }
   v->Synchronize(VisitorSynchronization::kGlobalHandles);
 
+  // Iterate over eternal handles.
+  isolate_->eternal_handles()->IterateAllRoots(v);
+  v->Synchronize(VisitorSynchronization::kEternalHandles);
+
   // Iterate over pointers being held by inactive threads.
   isolate_->thread_manager()->Iterate(v);
   v->Synchronize(VisitorSynchronization::kThreadManager);