f0377b2f92
... as part of adding NNBD as outlined in https://github.com/dart-lang/language/issues/110 This only supports parsing simple nullable types such as int? and List<int>? while subsequent CLs will add support for parsing more complex types. Due to current parser limitations, it also only supports nullable types in a limited number of statements such as T? t; if (x is String?) {} In addition, address comments in * https://dart-review.googlesource.com/c/sdk/+/87880 * https://dart-review.googlesource.com/c/sdk/+/87881 Change-Id: Ife4afadc0b72906fc0c4e9b1977ad838041c2a84 Reviewed-on: https://dart-review.googlesource.com/c/87920 Reviewed-by: Brian Wilkerson <brianwilkerson@google.com> Commit-Queue: Dan Rubel <danrubel@google.com>