[turbofan] Introduce JSCallForwardVarargs operator.

src/code-factory.h

Index: src/code-factory.h
diff --git a/src/code-factory.h b/src/code-factory.h
index 0c9048eade15d0ba878c7e39c2905f2a86245947..9f05c32aaf2f9c33161ef7088f5fbe3f6dddfee5 100644
--- a/src/code-factory.h
+++ b/src/code-factory.h
@@ -168,6 +168,8 @@ class V8_EXPORT_PRIVATE CodeFactory final {
   static Callable CallWithSpread(Isolate* isolate);
   static Callable CallFunction(
       Isolate* isolate, ConvertReceiverMode mode = ConvertReceiverMode::kAny);
+  static Callable CallForwardVarargs(Isolate* isolate);
+  static Callable CallFunctionForwardVarargs(Isolate* isolate);
   static Callable Construct(Isolate* isolate);
   static Callable ConstructWithSpread(Isolate* isolate);
   static Callable ConstructFunction(Isolate* isolate);