Remove hash_value(const llvm::Optional<T> &opt) in favor of LLVM's
Remove hash_value(const llvm::Optional<T> &opt) in favor of LLVM's

benlangmuir/swift,ahoppen/swift,glessard/swift,tkremenek/swift,xwu/swift,rudkx/swift,parkera/swift,atrick/swift,roambotics/swift,JGiola/swift,tkremenek/swift,parkera/swift,xwu/swift,benlangmuir/swift,parkera/swift,roambotics/swift,roambotics/swift,gregomni/swift,tkremenek/swift,glessard/swift,atrick/swift,hooman/swift,glessard/swift,rudkx/swift,apple/swift,tkremenek/swift,xwu/swift,hooman/swift,hooman/swift,hooman/swift,apple/swift,hooman/swift,gregomni/swift,ahoppen/swift,rudkx/swift,JGiola/swift,apple/swift,rudkx/swift,benlangmuir/swift,ahoppen/swift,apple/swift,xwu/swift,parkera/swift,atrick/swift,glessard/swift,benlangmuir/swift,roambotics/swift,benlangmuir/swift,xwu/swift,glessard/swift,JGiola/swift,JGiola/swift,ahoppen/swift,gregomni/swift,tkremenek/swift,rudkx/swift,glessard/swift,ahoppen/swift,xwu/swift,JGiola/swift,benlangmuir/swift,parkera/swift,gregomni/swift,parkera/swift,hooman/swift,gregomni/swift,hooman/swift,tkremenek/swift,roambotics/swift,parkera/swift,apple/swift,atrick/swift,tkremenek/swift,ahoppen/swift,rudkx/swift,xwu/swift,apple/swift,atrick/swift,JGiola/swift,atrick/swift,gregomni/swift,roambotics/swift,parkera/swift