[ConstraintSystem] Avoid using a separate set to compute viable defaults
[ConstraintSystem] Avoid using a separate set to compute viable defaults

apple/swift,hooman/swift,atrick/swift,atrick/swift,parkera/swift,gregomni/swift,gregomni/swift,xwu/swift,roambotics/swift,benlangmuir/swift,hooman/swift,parkera/swift,glessard/swift,JGiola/swift,tkremenek/swift,JGiola/swift,JGiola/swift,glessard/swift,tkremenek/swift,xwu/swift,rudkx/swift,glessard/swift,tkremenek/swift,gregomni/swift,roambotics/swift,jmgc/swift,xwu/swift,apple/swift,tkremenek/swift,gregomni/swift,tkremenek/swift,parkera/swift,rudkx/swift,parkera/swift,parkera/swift,JGiola/swift,jmgc/swift,roambotics/swift,rudkx/swift,apple/swift,jmgc/swift,benlangmuir/swift,jmgc/swift,gregomni/swift,benlangmuir/swift,roambotics/swift,JGiola/swift,roambotics/swift,hooman/swift,hooman/swift,rudkx/swift,benlangmuir/swift,jmgc/swift,JGiola/swift,benlangmuir/swift,benlangmuir/swift,parkera/swift,gregomni/swift,xwu/swift,hooman/swift,ahoppen/swift,roambotics/swift,tkremenek/swift,rudkx/swift,hooman/swift,glessard/swift,hooman/swift,jmgc/swift,apple/swift,ahoppen/swift,atrick/swift,atrick/swift,ahoppen/swift,xwu/swift,atrick/swift,glessard/swift,parkera/swift,xwu/swift,jmgc/swift,rudkx/swift,glessard/swift,ahoppen/swift,apple/swift,ahoppen/swift,atrick/swift,parkera/swift,ahoppen/swift,tkremenek/swift,apple/swift,xwu/swift