Adds:
- dart2aot, a script similar to dart2js which compiles my.dart to my.dart.aot.
- dartaotruntime, a minimal Dart runtime that only runs AOT blobs.
- some extra tooling like gen_kernel and gen_snapshot used by the above.
- build rules for all of the above, including adding it to the full SDK builds.
Bug:https://github.com/dart-lang/sdk/issues/27596
Change-Id: Ic35f832b2b86be959212b8d21cfc5a082da5ced4
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/97627
Reviewed-by: Alexander Thomas <athom@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
Commit-Queue: Clement Skau <cskau@google.com>
