Wrapping a legacy type will cause the legacy-ness to be stripped off by design.
This causes confusion when trying to unit test the runtime subtype checks so we
are now simply avoiding it here.
Introduce a `unwrap()` helper method that will attempt to upwrap any type that
isn't legacy. Legacy types are simply returned unchanged because they are
already unwrapped.
Copies the other helper methods from runtime_utils.dart to
runtime_utils_nnbd.dart so they can be updated with the special unwrapping logic
for legacy types.
Change-Id: I21ff24b766a1f7a569181a2e1c47233320751c66
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/131707
Reviewed-by: Sigmund Cherem <sigmund@google.com>
Reviewed-by: Mark Zhou <markzipan@google.com>
Commit-Queue: Nicholas Shahan <nshahan@google.com>
Nicholas Shahan
773ebd220b