Decorating a field with 'vm:shared' pragma makes values in this field accessible to all isolates in an isolate group.
Introduce `channel` to the `Version` class so that the pragma can only be enabled on main and dev channels.
TEST=shared_test, shared_fail_without_flag_test
BUG=https://github.com/dart-lang/sdk/issues/55991
Change-Id: I843c9f0d2ffc9f2ced7ddc4006bb6f9ca4e2ddf4
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/370064
Reviewed-by: Slava Egorov <vegorov@google.com>
Commit-Queue: Alexander Aprelev <aam@google.com>
Alexander Aprelev