Use Cell instead of AtomicUsize in RcCounter. (#646) r=rnewman
Use Cell instead of AtomicUsize in RcCounter. (#646) r=rnewman


ncalexan/mentat,mozilla/mentat,ncalexan/mentat,ncalexan/mentat,ncalexan/mentat,ncalexan/datomish,mozilla/mentat,mozilla/mentat,ncalexan/mentat,mozilla/mentat,ncalexan/datomish,mozilla/mentat,ncalexan/mentat,mozilla/mentat