swift

4bc1abb4 - Sema: Relax feature check for non-escapable types in swiftinterfaces.

Sema: Relax feature check for non-escapable types in swiftinterfaces. Checking for the presence of a feature flag in order to allow syntax tends to result in condfails when applied to `.swiftinterfaces`, since older compilers that have this restriction may be used to compile newer interfaces where the restriction has been lifted. Remove this restriction for non-escapable types when typechecking an interface. Resolves rdar://128577611