Update benchmark/single-source/BufferFill.swift
Update benchmark/single-source/BufferFill.swift

Co-authored-by: Karoy Lorentey <99005c9dd4d9ff2115d75dab502baba69bb0ee75@apple.com>
ahoppen/swift,rudkx/swift,benlangmuir/swift,ahoppen/swift,xwu/swift,atrick/swift,glessard/swift,benlangmuir/swift,JGiola/swift,atrick/swift,atrick/swift,hooman/swift,apple/swift,apple/swift,roambotics/swift,glessard/swift,xwu/swift,roambotics/swift,hooman/swift,apple/swift,atrick/swift,apple/swift,rudkx/swift,benlangmuir/swift,roambotics/swift,ahoppen/swift,atrick/swift,gregomni/swift,xwu/swift,roambotics/swift,JGiola/swift,gregomni/swift,gregomni/swift,roambotics/swift,rudkx/swift,hooman/swift,xwu/swift,ahoppen/swift,xwu/swift,apple/swift,glessard/swift,ahoppen/swift,apple/swift,glessard/swift,gregomni/swift,rudkx/swift,JGiola/swift,benlangmuir/swift,gregomni/swift,roambotics/swift,hooman/swift,JGiola/swift,xwu/swift,hooman/swift,rudkx/swift,ahoppen/swift,xwu/swift,hooman/swift,glessard/swift,JGiola/swift,benlangmuir/swift,rudkx/swift,glessard/swift,atrick/swift,hooman/swift,JGiola/swift,gregomni/swift,benlangmuir/swift