Avoid fast short-cut in Map::GeneralizeRepresentation() for literals with non-simple transitions.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index aba2cc923f5b82fa2cb00bb56c580d66a9c3ff56..e177cb56110ed3a16571755e4ad4badc9bdc1d24 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -5825,8 +5825,8 @@ class Map: public HeapObject {
       Handle<HeapType> type1,
       Handle<HeapType> type2,
       Isolate* isolate);
-  static void GeneralizeFieldType(Handle<Map> map,
-                                  int modify_index,
+  static void GeneralizeFieldType(Handle<Map> map, int modify_index,
+                                  Representation new_representation,
                                   Handle<HeapType> new_field_type);
   static Handle<Map> GeneralizeRepresentation(
       Handle<Map> map,
@@ -6377,6 +6377,7 @@ class Map: public HeapObject {
   Map* FindLastMatchMap(int verbatim, int length, DescriptorArray* descriptors);
 
   void UpdateFieldType(int descriptor_number, Handle<Name> name,
+                       Representation new_representation,
                        Handle<HeapType> new_type);
 
   void PrintGeneralization(FILE* file,