Tests: Add test cases for potential unavailability in class inheritance when  is specified.
Tests: Add test cases for potential unavailability in class inheritance when  is specified.

glessard/swift,glessard/swift,ahoppen/swift,JGiola/swift,ahoppen/swift,benlangmuir/swift,JGiola/swift,ahoppen/swift,roambotics/swift,benlangmuir/swift,glessard/swift,benlangmuir/swift,apple/swift,benlangmuir/swift,apple/swift,apple/swift,roambotics/swift,ahoppen/swift,JGiola/swift,roambotics/swift,JGiola/swift,apple/swift,ahoppen/swift,glessard/swift,JGiola/swift,glessard/swift,apple/swift,benlangmuir/swift,benlangmuir/swift,roambotics/swift,roambotics/swift,roambotics/swift,ahoppen/swift,JGiola/swift,glessard/swift,apple/swift