2958e80671
Change some of the straightforward collections to use spreads, for elements, and conditional elements. Many of the patterns in this file can't be translated because they are more complex - keep the simple ones with a declarative structure so that it is more clear when there are extra computations or side effects that are meaningful. Change-Id: I135b10641f61fc43ebbc4bbd7196c315339c3ee8 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/104103 Commit-Queue: Nate Bosch <nbosch@google.com> Reviewed-by: Mark Zhou <markzipan@google.com>