Lasse R.H. Nielsen
0c05e33836
Mark all currently unimplementable types as `final`, or `sealed` for `num` and `final` for `Function`. Mark all current classes intended as mixins as `mixin class`. More additions and cleanup will follow, but this change should make everything keep working as today if we flip the switch. TEST= No new tests, very little actual change, covered by existing tests with few changes. Will add more tests when adding more modifiers. Change-Id: I40e724f823e7f88cdef186d2f73874df256e2f43 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/281683 Reviewed-by: Siva Annamalai <asiva@google.com> Reviewed-by: Konstantin Shcheglov <scheglov@google.com> Reviewed-by: Aske Simon Christensen <askesc@google.com> Reviewed-by: Slava Egorov <vegorov@google.com> Commit-Queue: Lasse Nielsen <lrn@google.com> Reviewed-by: Sigmund Cherem <sigmund@google.com> Reviewed-by: Johnni Winther <johnniwinther@google.com> Reviewed-by: Kallen Tu <kallentu@google.com>