Executor for dart_native needs environment setup to execute

[sven-oly]

Testdriver with dart_native gives this in Linux environment. This needs to be fixed to run dart_native tests.

----> STDOUT= ><

!!!!!! !!!! ERROR IN EXECUTION: 255. STDERR = Unhandled exception:
UnimplementedError: Insert diplomat bindings here
#0 Collation4X.compareImpl (package:intl4x/src/collation/collation_4x.dart:16)
#1 Collation.compare (package:intl4x/src/collation/collation.dart:28)
#2 testCollator (file:///usr/local/google/home/ccornelius/ICU_conformance/conformance/executors/dart_native/bin/executor.dart:74)
#3 main. (file:///usr/local/google/home/ccornelius/ICU_conformance/conformance/executors/dart_native/bin/executor.dart:49)
#4 _RootZone.runUnaryGuarded (dart:async/zone.dart:1594)
#5 _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:339)
#6 _BufferingStreamSubscription._add (dart:async/stream_impl.dart:271)
#7 _SyncStreamControllerDispatch._sendData (dart:async/stream_controller.dart:776)
#8 _StreamController._add (dart:async/stream_controller.dart:650)
#9 _StreamController.add (dart:async/stream_controller.dart:598)
#10 _Socket._onData (dart:io-patch/socket_patch.dart:2381)
#11 _RootZone.runUnaryGuarded (dart:async/zone.dart:1594)
#12 _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:339)
#13 _BufferingStreamSubscription._add (dart:async/stream_impl.dart:271)
#14 _SyncStreamControllerDispatch._sendData (dart:async/stream_controller.dart:776)
#15 _StreamController._add (dart:async/stream_controller.dart:650)
#16 _StreamController.add (dart:async/stream_controller.dart:598)
#17 new _RawSocket. (dart:io-patch/socket_patch.dart:1899)
#18 _NativeSocket.issueReadEvent.issue (dart:io-patch/socket_patch.dart:1356)
#19 _microtaskLoop (dart:async/schedule_microtask.dart:40)
#20 _startMicrotaskLoop (dart:async/schedule_microtask.dart:49)
#21 _runPendingImmediateCallback (dart:isolate-patch/isolate_patch.dart:123)
#22 _RawReceivePort._handleMessage (dart:isolate-patch/isolate_patch.dart:190)
WARNING:root:!!!!!! process_batch_of_tests: "platform error": "!!!! ERROR IN EXECUTION: 255. STDERR = Unhandled exception:
UnimplementedError: Insert diplomat bindings here
#0 Collation4X.compareImpl (package:intl4x/src/collation/collation_4x.dart:16)
#1 Collation.compare (package:intl4x/src/collation/collation.dart:28)
#2 testCollator (file:///usr/local/google/home/ccornelius/ICU_conformance/conformance/executors/dart_native/bin/executor.dart:74)
#3 main. (file:///usr/local/google/home/ccornelius/ICU_conformance/conformance/executors/dart_native/bin/executor.dart:49)
#4 _RootZone.runUnaryGuarded (dart:async/zone.dart:1594)
#5 _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:339)
#6 _BufferingStreamSubscription._add (dart:async/stream_impl.dart:271)
#7 _SyncStreamControllerDispatch._sendData (dart:async/stream_controller.dart:776)
#8 _StreamController._add (dart:async/stream_controller.dart:650)
#9 _StreamController.add (dart:async/stream_controller.dart:598)
#10 _Socket._onData (dart:io-patch/socket_patch.dart:2381)
#11 _RootZone.runUnaryGuarded (dart:async/zone.dart:1594)
#12 _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:339)
#13 _BufferingStreamSubscription._add (dart:async/stream_impl.dart:271)
#14 _SyncStreamControllerDispatch._sendData (dart:async/stream_controller.dart:776)
#15 _StreamController._add (dart:async/stream_controller.dart:650)
#16 _StreamController.add (dart:async/stream_controller.dart:598)
#17 new _RawSocket. (dart:io-patch/socket_patch.dart:1899)
#18 _NativeSocket.issueReadEvent.issue (dart:io-patch/socket_patch.dart:1356)
#19 _microtaskLoop (dart:async/schedule_microtask.dart:40)
#20 _startMicrotaskLoop (dart:async/schedule_microtask.dart:49)
#21 _runPendingImmediateCallback (dart:isolate-patch/isolate_patch.dart:123)
#22 _RawReceivePort._handleMessage (dart:isolate-patch/isolate_patch.dart:190)
"

[sffc]

@mosuem Are we still running Dart Native testing? We should try to make sure this is running in CI and appearing on the dashboard.