b0a34dbccb
Closes https://github.com/dart-lang/linter/issues/4841 Adds a lint to verify and report whether an is check or a cast may result in platform-inconsistent behavior. In order to do so, adds necessary additions to canBeSubtypeOf and extends the mock SDK. Also adds this to the list of default rules. Change-Id: I7f235ee698419d9f253cc96f08322bedca271825 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/361722 Reviewed-by: Sigmund Cherem <sigmund@google.com> Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>