[v6.d REVIEW] Precisify :close on words
[v6.d REVIEW] Precisify :close on words

- Spec partial consumption of iterator leaves the handle in
    open state
- Spec consuming $limit items from iterator closes the handle
    even before we got IterationEnd

Orig: https://github.com/perl6/roast/commit/b0c4a7a37

dogbert17/roast,perl6/roast,dogbert17/roast