[ros-diffs] [fireball] 29244: - Fix multiple bugs in RtlWalkFrameChain and secure it against any possibility of a bugcheck while walking the stack. - Fix bugs in RtlUnwind and RtlExceptionDispatch which assumed the DPC stack size was 4KB instead of 12KB. - Fix multiple bugs in RtlpGetStackLimits and seure it against bugchecks. Properly detect DPC or invalid stacks. - PsConvertToGuiThread should acquire a guarded region, not a critical section, to stop all APCs. - Fix bug in bugzilla reporting which was maki