Move loop-breaker info from original function to worker in work/wrap

When doing a w/w split, if the original function is a loop breaker
then the worker (not the wrapper) becomes one instead.

This isn't very important, because loop breaker information is
recalculated afresh by the occurrence analyser, but it seems more
kosher.  And Lint was bleating piteously about things with InlineRules
that were loop breakers.