Change abefb7b432 introduced a typing issue
instead of fixing it: _SyncIterator<T>._current was actually used to return
either a value of type T (for yield) or value of type Iterable<T> (for yield*)
from the move callback.
This change refactors implementation of _SyncIterator in such a way that
_current is only used to return value for yield and a separate field
_yieldEachIterable is used to return Iterable<T> for yield*.
Change-Id: I3e3c832bbc8986d6976ddbb0856a1b5a127d845b
Reviewed-on: https://dart-review.googlesource.com/15542
Commit-Queue: Vyacheslav Egorov <vegorov@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Vyacheslav Egorov
9cd7bc724d