[Merge] Make &CORE:: subs respect vmsish hints

Most lexical hints are stored in the statement’s nextstate(ment)
op (aka cop or control op).  That op is available at run time as
PL_curcop, while the current op being executed is PL_op.

&CORE:: subs intentionally lack a nextstate op so they can see the
hints in the caller’s nextstate op.

Two vmsish hints were being stored in the current op, so &CORE::exit()
would not respect those hints, as &CORE::exit() executes the *same*
exit op each time.

This branch moves those hints to the nextstate op, so that &CORE::exit
behaves the same way as exit().