<rdar://problem/3889696> Enable conservative garbage collection for JavaScript

	* kjs/collector.cpp:
        (KJS::Collector::Thread::Thread):
        (KJS::destroyRegisteredThread):
        (KJS::initializeRegisteredThreadKey):
        (KJS::Collector::registerThread):
        (KJS::Collector::markStackObjectsConservatively):
        (KJS::Collector::markCurrentThreadConservatively):
        (KJS::Collector::markOtherThreadConservatively):
        * kjs/collector.h:
        * kjs/internal.cpp:
        (lockInterpreter):
        * kjs/value.h:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@8067 268f45cc-cd09-0410-ab3c-d52691b4dbfc