[es6] Fix Function and GeneratorFunction built-ins subclassing.

src/factory.h

Index: src/factory.h
diff --git a/src/factory.h b/src/factory.h
index 22baf4534730664888229aeadaabd13cfcb55545..63af855f5eb7359aec49530779ca700a6b50a1e6 100644
--- a/src/factory.h
+++ b/src/factory.h
@@ -505,8 +505,11 @@ class Factory final {
                                                  bool is_strict = false);
 
   Handle<JSFunction> NewFunctionFromSharedFunctionInfo(
-      Handle<SharedFunctionInfo> function_info,
-      Handle<Context> context,
+      Handle<Map> initial_map, Handle<SharedFunctionInfo> function_info,
+      Handle<Context> context, PretenureFlag pretenure = TENURED);
+
+  Handle<JSFunction> NewFunctionFromSharedFunctionInfo(
+      Handle<SharedFunctionInfo> function_info, Handle<Context> context,
       PretenureFlag pretenure = TENURED);
 
   Handle<JSFunction> NewFunction(Handle<String> name, Handle<Code> code,