Reland "[strong] Object literals create strong objects"

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 645ea57e344d2727209c68fa90b4a98843108d0e..28670a94f758aa7d00054ee3514101cf65a04ef3 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -3804,7 +3804,9 @@ 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);
@@ -10318,7 +10320,10 @@ 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;
 }
 
@@ -10353,13 +10358,18 @@ 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.
-      Context* native_context = function->context()->native_context();
-      Object* array_function =
-          native_context->get(Context::ARRAY_FUNCTION_INDEX);
+      // updated initial maps (and transitioned versions) in the native context.
+      Handle<Context> native_context(function->context()->native_context(),
+                                     isolate);
+      Handle<Object> array_function(
+          native_context->get(Context::ARRAY_FUNCTION_INDEX), isolate);
       if (array_function->IsJSFunction() &&
-          *function == JSFunction::cast(array_function)) {
-        CacheInitialJSArrayMaps(handle(native_context, isolate), new_map);
+          *function == JSFunction::cast(*array_function)) {
+        CacheInitialJSArrayMaps(native_context, new_map);
+        Handle<Map> new_strong_map =
+            Map::Copy(initial_map, "SetInstancePrototype");
+        new_strong_map->set_is_strong(true);
+        CacheInitialJSArrayMaps(native_context, new_strong_map);
       }
     }