ClangImporter: repair a merge conflict
ClangImporter: repair a merge conflict

`llvm::make_unique` has been replaced with `std::make_unique`.  Adjust
the master-next branch accordingly.

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