Reland "[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 a54151d2a9072ca8d2d17362fb0e84c9091e9f1d..80916b8a20d075c443864785d98257f2e07523ce 100644
--- a/src/factory.h
+++ b/src/factory.h
@@ -507,8 +507,11 @@ 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,