Changed the classes to store induced modifiers on `isBase`, `isFinal`, and `isInterface`. If one of these getters are true and `isSealed` is true, then we assume it's an induced modifier. (Since a class or mixin cannot be both sealed and another modifier).
There's a subtle change here where the induced modifiers are only marked on sealed classes which means that classes that subclass/subtype non-sealed classes won't get any base or final errors. This will also affect how lints will be reported -- at the next erroneous subtype and not downstream from that type.
Also, the context messages now point to the class with the explicit modifier inciting the error.
Bug: #51671
Change-Id: I4c7541d956382dcb3917a4b8d73756840880c52f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/289406
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Reviewed-by: Phil Quitslund <pquitslund@google.com>
Kallen Tu
fde66e95bd