Make claim2live and tlrClaim2live use lazySet
Make BSlot extend AtomicInteger
Merge branch 'perf/lazy-set' into perf/extend-atomicint-and-lazyset
Extract slow-path out of claim
Merge branch 'perf/extend-atomicint-and-lazyset' into perf/extract-slowpath-lazyset
Remove the explicit branch check for the poison pill

It's faster to let it be conditionally implied by the presence of poison on a slot.
One less conditional jump in the fast-path, basically.