IRGen: Refactor getObjCEncodingForMethod and getObjectEncodingFromClangNode into one
IRGen: Refactor getObjCEncodingForMethod and getObjectEncodingFromClangNode into one

NFC.

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