for static attributes in supplemental IDL files
https://bugs.webkit.org/show_bug.cgi?id=91925

Reviewed by Adam Barth.

r122912 implemented static attributes in CodeGeneratorJS.pm.
However, it generates wrong code for static attributes in supplemental
IDL files. This patch fixes it as shown in JSTestInterface.cpp.
This fix aligns with the fix in CodeGeneratorV8.pm (r123308).

Test: bindings/scripts/test/TestSupplemental.idl

* bindings/scripts/CodeGeneratorJS.pm:
(GenerateImplementation):
* bindings/scripts/test/JS/JSTestInterface.cpp:
(WebCore::jsTestInterfaceConstructorSupplementalStaticReadOnlyAttr):
(WebCore::jsTestInterfaceConstructorSupplementalStaticAttr):
(WebCore::setJSTestInterfaceConstructorSupplementalStaticAttr):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@123439 268f45cc-cd09-0410-ab3c-d52691b4dbfc