Stores and compound assignments for named super properties.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index e2321974d3fb03c7b92fc726f3f1fa2411dc1d61..f2e17d34bb540eac78e0f0c324d31bbd7f2ee022 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -1007,6 +1007,8 @@ class Object {
     CERTAINLY_NOT_STORE_FROM_KEYED
   };
 
+  enum StorePropertyMode { NORMAL_PROPERTY, SUPER_PROPERTY };
+
   INLINE(bool IsFixedArrayBase() const);
   INLINE(bool IsExternal() const);
   INLINE(bool IsAccessorInfo() const);
@@ -1116,7 +1118,8 @@ class Object {
 
   MUST_USE_RESULT static MaybeHandle<Object> SetProperty(
       LookupIterator* it, Handle<Object> value, StrictMode strict_mode,
-      StoreFromKeyed store_mode);
+      StoreFromKeyed store_mode,
+      StorePropertyMode data_store_mode = NORMAL_PROPERTY);
   MUST_USE_RESULT static MaybeHandle<Object> WriteToReadOnlyProperty(
       LookupIterator* it, Handle<Object> value, StrictMode strict_mode);
   static Handle<Object> SetDataProperty(LookupIterator* it,