[perl #122504] [BUG] 'return' invoked outside of a routine should throw an exception

[Sam S. via RT]

A `return` outside a routine now always seems to throw a run-time error, as it 
should:

    $  perl6 -e 'return'   
    Attempt to return outside of any Routine
      in block <unit> at -e line 1

    $  perl6 -e '{ return }' 
    Attempt to return outside of any Routine
      in block <unit> at -e line 1

    $  MVM_SPESH_DISABLE=1 perl6 -e '{ return }'
    Attempt to return outside of any Routine
      in block <unit> at -e line 1

Bisectable points to this fix from Dec 2015:

    https://gist.github.com/Whateverable/63b5da597e229d167d8708a43d4501de
    https://github.com/rakudo/rakudo/commit/a4ca12a

This ticket can be closed once tests are added to roast.