swift

a03c40cb - [ClangImporter] Classify enums using flag_enum and enum_extensibility (#8910)

[ClangImporter] Classify enums using flag_enum and enum_extensibility (#8910) These new Clang attributes identify whether an enum is intended to represent an option set or not, and whether the set of cases listed in the enum declaration is exhaustive. (Swift doesn't currently have a closed/open distinction for enums, so treat any C enum with enum_extensibility as a proper closed Swift enum, like we do with NS_ENUM.) Enums with neither attribute will continue to be imported as unique types. rdar://problem/28476618