Creates an external createDartExport function in js_util.
Adds a number of checks for the annotation:
- Classes with the annotation should not have value in the annotation
- Classes with the annotation should have at least one instance member
somewhere in the hierarchy
- There are no export name collisions that are unresolvable accounting
for overrides
- Members with this annotation are instance members with a body only
Also adds checks to createDartExport:
- Checks that the type is a Dart class
- Checks that the type is marked as exportable
Change-Id: I52f27275966e9603e88921ce7897b7615178c4d2
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/259511
Reviewed-by: Riley Porter <rileyporter@google.com>
Reviewed-by: Sigmund Cherem <sigmund@google.com>
Srujan Gaddam
7f93985005