cps.runtime.util.control

This wrapper for control exception, which is handled by NonFatal(ex)

The main reason for it;'s existence, that we can't rewrite all monadic operation to handle NonFatalOnly throwables instead NonFatal. (The right way will be to change monadic operations in standard library, but this is a long way. )

So, for supports of returning and break clauses, we change NonLocalReturns.throwReturn(ce) to NonLocalReturnsShift.throwAsyncWrapperReturn(ce)