Make CodeGeneratorJS plant comments to explain failures in the binding validation
https://bugs.webkit.org/show_bug.cgi?id=114528

Reviewed by Sam Weinig.

No change in behaviour, just make the generated bindings include comments
to aid diagnosing issues that may be non-obvious.

* bindings/scripts/CodeGeneratorJS.pm:
(GenerateImplementation):
* bindings/scripts/test/JS/JSTestActiveDOMObject.cpp:
(WebCore::toJS):
* bindings/scripts/test/JS/JSTestCustomNamedGetter.cpp:
(WebCore::toJS):
* bindings/scripts/test/JS/JSTestEventConstructor.cpp:
(WebCore::toJS):
* bindings/scripts/test/JS/JSTestEventTarget.cpp:
(WebCore::toJS):
* bindings/scripts/test/JS/JSTestException.cpp:
(WebCore::toJS):
* bindings/scripts/test/JS/JSTestInterface.cpp:
(WebCore::toJS):
* bindings/scripts/test/JS/JSTestMediaQueryListListener.cpp:
(WebCore::toJS):
* bindings/scripts/test/JS/JSTestNamedConstructor.cpp:
(WebCore::toJS):
* bindings/scripts/test/JS/JSTestObj.cpp:
(WebCore::toJS):
* bindings/scripts/test/JS/JSTestOverloadedConstructors.cpp:
(WebCore::toJS):
* bindings/scripts/test/JS/JSTestSerializedScriptValueInterface.cpp:
(WebCore::toJS):
* bindings/scripts/test/JS/JSTestTypedefs.cpp:
(WebCore::toJS):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@148301 268f45cc-cd09-0410-ab3c-d52691b4dbfc