* Manual roll of Dart from 24c7666def...40fd1c456e

dart-lang/sdk@40fd1c456e Revert "[dart:io] Add Abort() on HttpClientRequest"
dart-lang/sdk@17d7296a42 [vm/nnbd/bytecode] Fix reuse of type arguments in bytecode
dart-lang/sdk@58b6f40c73 Issue 42797. Understand in legacy libraries that a function returning Never (in Null Safety library) never returns. (reland)
dart-lang/sdk@fc8a6d9f9b [VM/compiler] Dereference TypeRef literal when propagating constants.
dart-lang/sdk@0689ec527a Move "test.dart" (well, most of its contents) into pkg/test_runner.
dart-lang/sdk@1094b3c61d Prepare static error test updater tool to handle web tests.
dart-lang/sdk@b258585f2f [observatory] Migrate from deprecated isInstanceOf to isA.
dart-lang/sdk@dfe1d9b682 Disable OverrideContributor for Cider.
dart-lang/sdk@aea99b2f5c scope debug property assist to Diagnosticables
dart-lang/sdk@4b96f20a79 [dart:io] Add Abort() on HttpClientRequest
dart-lang/sdk@1b1a39708c [build] Use frameworks instead of libs
dart-lang/sdk@3fef522496 Revert "Reland "[vm] Replaces fuchsia.deprecatedtimezone""
dart-lang/sdk@8c664d4f3f Revert "Issue 42797. Understand in legacy libraries that a function returning Never (in Null Safety library) never returns."
dart-lang/sdk@2efb5bebc7 [ dart:_http ] Fix typo in HTTP response timeline event
dart-lang/sdk@0884dae36c Revert "Fix the #include path for ICU headers"
dart-lang/sdk@5171534e81 Scope tweaks. Report REFERENCED_BEFORE_DECLARATION in more places.
dart-lang/sdk@6bba75079a Issue 42797. Understand in legacy libraries that a function returning Never (in Null Safety library) never returns.
dart-lang/sdk@b4ebbb7f5c [build] Update gn to match Fuchsia
dart-lang/sdk@cb428a7a02 [dart2js] Remove old bug work around in collector.
dart-lang/sdk@08663c20ab Change flutter patch to match existing DEPS on master branch
dart-lang/sdk@146ad014d9 update js/meta for the 2.10 dev sdk
dart-lang/sdk@488c718793 [co19] Roll co19 to d79951e06e443213243e54c2c32694b79a221b65
dart-lang/sdk@ba20edd7be Add patch for flutter-engine when changing to version 2.10

* Rev buildroot to latest version.

* Update license.

* update.

* Update gn revision.

* Format BUILD.gn files as the gn revision has been updated.

Work towards flutter/flutter#60999

All usage of .packages must eventually be replace with package_config.json to support language versioning.

This was only necessary when the Engine had to build in multiple buildroots
where the sources where checked out at different paths relative to the
buildroot. This is no longer the case and there are already cases GN rules
have been written that mix and match variable usage with the direct
specification of the path to the Flutter sources relative to the sole buildroot.

* [dart_aot_runner] Complete the port of dart_aot_runner

- also adds the previously missing profiler symbols for dart_jit_runner
- CIPD package will contain both the JIT and AOT dart runners

* specify the inputs

Ported from the original implementation in the Topaz tree.