[cxx-interop] Fix test failures with older libstdc++
[cxx-interop] Fix test failures with older libstdc++

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