- fix <rdar://problem/5371862> crash in Dashcode due to Quartz Composer JavaScript garbage collector reentrancy

        * API/JSBase.cpp: (JSGarbageCollect): Don't call collector() if isBusy() returns true.

        * kjs/collector.h: Added isBusy(), removed the unused return value from collect()
        * kjs/collector.cpp: Added an "operation in progress" flag to the allocator.
        (KJS::Collector::allocate): Call abort() if an operation is already in progress. Set the new flag instead
        of using the debug-only GCLock.
        (KJS::Collector::collect): Ditto.
        (KJS::Collector::isBusy): Added.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@24874 268f45cc-cd09-0410-ab3c-d52691b4dbfc