[stubs] Port KeyedStoreIC_Megamorphic stub to Turbofan

src/code-factory.cc

Index: src/code-factory.cc
diff --git a/src/code-factory.cc b/src/code-factory.cc
index d85fd6312aa4fdbe97b0641c16963b605ac6ac78..b6eb1744d4b8d82beea997d6b561a76a54205ebd 100644
--- a/src/code-factory.cc
+++ b/src/code-factory.cc
@@ -123,6 +123,13 @@ Callable CodeFactory::KeyedStoreICInOptimizedCode(Isolate* isolate,
 // static
 Callable CodeFactory::KeyedStoreIC_Megamorphic(Isolate* isolate,
                                                LanguageMode language_mode) {
+  if (FLAG_tf_store_ic_stub) {
+    return Callable(
+        language_mode == STRICT
+            ? isolate->builtins()->KeyedStoreIC_Megamorphic_Strict_TF()
+            : isolate->builtins()->KeyedStoreIC_Megamorphic_TF(),
+        StoreWithVectorDescriptor(isolate));
+  }
   return Callable(language_mode == STRICT
                       ? isolate->builtins()->KeyedStoreIC_Megamorphic_Strict()
                       : isolate->builtins()->KeyedStoreIC_Megamorphic(),