https://bugs.webkit.org/show_bug.cgi?id=101989.

Reviewed by Geoffrey Garen.

Source/JavaScriptCore: 

Added infrastructure for scanning weak ref slots.

* heap/SlotVisitor.cpp: Added #include "SlotVisitorInlines.h".
* heap/SlotVisitor.h:
(SlotVisitor): Added SlotVisitor::appendUnbarrieredWeak().
* heap/SlotVisitorInlines.h: Added #include "Weak.h".
(JSC::SlotVisitor::appendUnbarrieredWeak): Added.
* heap/Weak.h:
(JSC::operator==): Added operator==() for Weak.
* runtime/JSCell.h: Removed #include "SlotVisitorInlines.h".
* runtime/JSObject.h: Added #include "SlotVisitorInlines.h".

Source/WebCore: 

No new tests.

* ForwardingHeaders/heap/SlotVisitor.h: Added.
* bindings/js/JSDOMBinding.h: Added #include <heap/SlotVisitor.h>
* bindings/js/JSEventListener.cpp:
(WebCore::JSEventListener::JSEventListener):
(WebCore::JSEventListener::visitJSFunction):
(WebCore::JSEventListener::operator==):
 - Removed the m_wrapper checks in operator==() because they are not
   needed. There is no longer any threat of m_jsFunction pointing to
   recycled memory. The use of weak refs will ensure that m_jsFunction
   is either still holding on to its old memory exclusively, or is 0'ed
   out when the GC collects it.
* bindings/js/JSEventListener.h:
(JSEventListener):
(WebCore::JSEventListener::jsFunction):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@134697 268f45cc-cd09-0410-ab3c-d52691b4dbfc