[stdlib][test] Add a bit more extensive tests for high-level set operations
[stdlib][test] Add a bit more extensive tests for high-level set operations

benlangmuir/swift,gregomni/swift,ahoppen/swift,atrick/swift,atrick/swift,JGiola/swift,rudkx/swift,roambotics/swift,roambotics/swift,benlangmuir/swift,benlangmuir/swift,glessard/swift,glessard/swift,benlangmuir/swift,JGiola/swift,JGiola/swift,apple/swift,rudkx/swift,roambotics/swift,atrick/swift,benlangmuir/swift,gregomni/swift,atrick/swift,JGiola/swift,glessard/swift,gregomni/swift,glessard/swift,rudkx/swift,rudkx/swift,JGiola/swift,apple/swift,ahoppen/swift,apple/swift,apple/swift,rudkx/swift,apple/swift,JGiola/swift,ahoppen/swift,roambotics/swift,atrick/swift,rudkx/swift,gregomni/swift,roambotics/swift,atrick/swift,apple/swift,ahoppen/swift,glessard/swift,gregomni/swift,ahoppen/swift,roambotics/swift,benlangmuir/swift,ahoppen/swift,gregomni/swift,glessard/swift