Do not copy the compiler-rt builtins if the destination directory doesn't exist
Do not copy the compiler-rt builtins if the destination directory doesn't exist

rdar://51963563

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