[IRGen] Remove an unused DenseMap
[IRGen] Remove an unused DenseMap

nathawes/swift,hooman/swift,jmgc/swift,glessard/swift,jmgc/swift,xwu/swift,glessard/swift,rudkx/swift,apple/swift,stephentyrone/swift,CodaFi/swift,apple/swift,xwu/swift,airspeedswift/swift,jckarter/swift,benlangmuir/swift,gregomni/swift,roambotics/swift,parkera/swift,jckarter/swift,allevato/swift,airspeedswift/swift,rudkx/swift,parkera/swift,CodaFi/swift,airspeedswift/swift,CodaFi/swift,airspeedswift/swift,ahoppen/swift,stephentyrone/swift,apple/swift,atrick/swift,gregomni/swift,benlangmuir/swift,allevato/swift,allevato/swift,glessard/swift,ahoppen/swift,JGiola/swift,jmgc/swift,atrick/swift,allevato/swift,parkera/swift,roambotics/swift,CodaFi/swift,JGiola/swift,nathawes/swift,parkera/swift,roambotics/swift,nathawes/swift,jmgc/swift,hooman/swift,tkremenek/swift,stephentyrone/swift,parkera/swift,rudkx/swift,parkera/swift,atrick/swift,jmgc/swift,JGiola/swift,hooman/swift,hooman/swift,tkremenek/swift,tkremenek/swift,tkremenek/swift,rudkx/swift,tkremenek/swift,allevato/swift,tkremenek/swift,airspeedswift/swift,glessard/swift,benlangmuir/swift,gregomni/swift,nathawes/swift,roambotics/swift,stephentyrone/swift,nathawes/swift,JGiola/swift,atrick/swift,xwu/swift,xwu/swift,glessard/swift,airspeedswift/swift,hooman/swift,benlangmuir/swift,nathawes/swift,gregomni/swift,xwu/swift,rudkx/swift,jckarter/swift,apple/swift,benlangmuir/swift,ahoppen/swift,apple/swift,roambotics/swift,roambotics/swift,gregomni/swift,stephentyrone/swift,jckarter/swift,jmgc/swift,xwu/swift,benlangmuir/swift,glessard/swift,allevato/swift,ahoppen/swift,CodaFi/swift,stephentyrone/swift,hooman/swift,parkera/swift,JGiola/swift,ahoppen/swift,tkremenek/swift,gregomni/swift,nathawes/swift,stephentyrone/swift,xwu/swift,atrick/swift,atrick/swift,jckarter/swift,allevato/swift,jckarter/swift,airspeedswift/swift,jmgc/swift,JGiola/swift,jckarter/swift,ahoppen/swift,rudkx/swift,hooman/swift,CodaFi/swift,CodaFi/swift,parkera/swift,apple/swift