Adds an interface which implements both `TypedData`
and `List`. That allows abstracting over types that are both
`List` and `TypedData` without losing access to one of the
interfaces.
Tested: typed_data_interface_test.dart
Change-Id: Idbdfc084ea5d2d9a072887973e2e9d29a5fd94ce
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/371100
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Lasse Nielsen <lrn@google.com>
Reviewed-by: Nate Bosch <nbosch@google.com>
Reviewed-by: Stephen Adams <sra@google.com>
