b3862d5a92
This prepares the generator to be implemented by the analyzer. Change-Id: Ia962668e1327b53af968be9efdc41ea6b124b4d0 Reviewed-on: https://dart-review.googlesource.com/56482 Reviewed-by: Dmitry Stefantsov <dmitryas@google.com> Commit-Queue: Peter von der Ahé <ahe@google.com>