Adds an experimental `@trustTypes` annotation which can be used during
migration to static interop to preserve the older semantics for JS interop.
Change-Id: Ic00a6c968b15f8c8f5d0840b82db5a6670eaf0eb
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/241362
Reviewed-by: Riley Porter <rileyporter@google.com>
Reviewed-by: Srujan Gaddam <srujzs@google.com>
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Commit-Queue: Joshua Litt <joshualitt@google.com>