Follow-up fix for:

Follow-up fix for:
JavaScript bindings are unnecessarily checking for impossible empty JSValue arguments
https://bugs.webkit.org/show_bug.cgi?id=145811

Reviewed by Antti Koivisto.

There was one unusual case in the bindings generator that was depending on this.

* bindings/js/JSDOMBinding.h:
(WebCore::argumentOrNull): Deleted.
* bindings/scripts/CodeGeneratorJS.pm:
(GenerateParametersCheck): Stop using argumentOrNull.
* bindings/scripts/test/JS/JSTestNamedConstructor.cpp: Updated.
* bindings/scripts/test/JS/JSTestObj.cpp: Updated.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@185377 268f45cc-cd09-0410-ab3c-d52691b4dbfc