[Constraint solver] Generate constraints for “is” patterns.
[Constraint solver] Generate constraints for “is” patterns.

Generate a checked-cast constraint for an “is” pattern, which otherwise
doesn’t change the type. This is hard to validate because checked-cast
constraints never actually fail.
CodaFi/swift,jckarter/swift,hooman/swift,benlangmuir/swift,atrick/swift,tkremenek/swift,allevato/swift,parkera/swift,nathawes/swift,harlanhaskins/swift,gregomni/swift,benlangmuir/swift,JGiola/swift,JGiola/swift,apple/swift,roambotics/swift,airspeedswift/swift,allevato/swift,nathawes/swift,xwu/swift,harlanhaskins/swift,JGiola/swift,atrick/swift,JGiola/swift,hooman/swift,ahoppen/swift,CodaFi/swift,CodaFi/swift,jckarter/swift,tkremenek/swift,rudkx/swift,stephentyrone/swift,aschwaighofer/swift,allevato/swift,parkera/swift,CodaFi/swift,nathawes/swift,jmgc/swift,glessard/swift,benlangmuir/swift,airspeedswift/swift,ahoppen/swift,rudkx/swift,CodaFi/swift,rudkx/swift,jmgc/swift,tkremenek/swift,xwu/swift,JGiola/swift,nathawes/swift,ahoppen/swift,harlanhaskins/swift,stephentyrone/swift,ahoppen/swift,stephentyrone/swift,jckarter/swift,xwu/swift,roambotics/swift,hooman/swift,hooman/swift,parkera/swift,jckarter/swift,gregomni/swift,stephentyrone/swift,jmgc/swift,ahoppen/swift,parkera/swift,glessard/swift,jckarter/swift,parkera/swift,stephentyrone/swift,glessard/swift,CodaFi/swift,airspeedswift/swift,atrick/swift,rudkx/swift,jckarter/swift,aschwaighofer/swift,stephentyrone/swift,tkremenek/swift,gregomni/swift,CodaFi/swift,apple/swift,airspeedswift/swift,harlanhaskins/swift,benlangmuir/swift,tkremenek/swift,airspeedswift/swift,gregomni/swift,xwu/swift,hooman/swift,allevato/swift,aschwaighofer/swift,jmgc/swift,hooman/swift,airspeedswift/swift,xwu/swift,jmgc/swift,glessard/swift,benlangmuir/swift,aschwaighofer/swift,benlangmuir/swift,atrick/swift,roambotics/swift,parkera/swift,parkera/swift,jmgc/swift,nathawes/swift,roambotics/swift,roambotics/swift,nathawes/swift,allevato/swift,atrick/swift,gregomni/swift,stephentyrone/swift,nathawes/swift,aschwaighofer/swift,apple/swift,airspeedswift/swift,gregomni/swift,JGiola/swift,glessard/swift,parkera/swift,jckarter/swift,rudkx/swift,aschwaighofer/swift,tkremenek/swift,tkremenek/swift,apple/swift,allevato/swift,harlanhaskins/swift,hooman/swift,atrick/swift,roambotics/swift,jmgc/swift,apple/swift,rudkx/swift,apple/swift,ahoppen/swift,glessard/swift,aschwaighofer/swift,harlanhaskins/swift,xwu/swift,xwu/swift,allevato/swift,harlanhaskins/swift