Something has changed about the CoreData module and caused the declarations in
this test interface to now be printed with `nonisolated` modifiers.
Resolves rdar://158783868.
Normally, we diagnose @NSManaged properties that have getters and
setters because they are actually supposed to be stored properties with
special synthesized accessors. Since we print those accessors in module
interfaces, just don't error when we see them.
Fixes rdar://56111556