CodeGeneratorJS.pm should generate "isFiringEventListeners()" check in isReachableFromOpaqueRoots()
https://bugs.webkit.org/show_bug.cgi?id=114784

Reviewed by Geoffrey Garen.

EventTarget subclasses shouldn't have to use CustomIsReachable directives
in order to keep their wrappers alive while firing event listeners.

* bindings/scripts/CodeGeneratorJS.pm:
(GenerateImplementation):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@148700 268f45cc-cd09-0410-ab3c-d52691b4dbfc