[strong] Object literals create strong objects

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 6dc5de2552847c8487da20604452705a7837143f..89129318636f220a40edb14061725d4b63b827ed 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -3800,7 +3800,9 @@ Handle<Map> Map::TransitionElementsTo(Handle<Map> map,
 
   Isolate* isolate = map->GetIsolate();
   Context* native_context = isolate->context()->native_context();
-  Object* maybe_array_maps = native_context->js_array_maps();
+  Object* maybe_array_maps = map->is_strong()
+      ? native_context->js_array_strong_maps()
+      : native_context->js_array_maps();
   if (maybe_array_maps->IsFixedArray()) {
     DisallowHeapAllocation no_gc;
     FixedArray* array_maps = FixedArray::cast(maybe_array_maps);
@@ -10314,7 +10316,10 @@ Handle<Object> CacheInitialJSArrayMaps(
     maps->set(next_kind, *new_map);
     current_map = new_map;
   }
-  native_context->set_js_array_maps(*maps);
+  if (initial_map->is_strong())
+    native_context->set_js_array_strong_maps(*maps);
+  else
+    native_context->set_js_array_maps(*maps);
   return initial_map;
 }
 
@@ -10349,13 +10354,18 @@ void JSFunction::SetInstancePrototype(Handle<JSFunction> function,
       JSFunction::SetInitialMap(function, new_map, value);
 
       // If the function is used as the global Array function, cache the
-      // initial map (and transitioned versions) in the native context.
+      // updated initial maps (and transitioned versions) in the native context.
       Context* native_context = function->context()->native_context();
       Object* array_function =
           native_context->get(Context::ARRAY_FUNCTION_INDEX);
       if (array_function->IsJSFunction() &&
           *function == JSFunction::cast(array_function)) {
         CacheInitialJSArrayMaps(handle(native_context, isolate), new_map);
+        Handle<Map> new_strong_map =
+            Map::Copy(initial_map, "SetInstancePrototype");
+        new_strong_map->set_is_strong(true);
+        CacheInitialJSArrayMaps(handle(native_context, isolate),
+                                new_strong_map);
       }
     }