[AutoDiff] NFC: gardening. (#28928)
[AutoDiff] NFC: gardening. (#28928)

Upstream minor changes from `tensorflow` branch.
harlanhaskins/swift,nathawes/swift,JGiola/swift,airspeedswift/swift,CodaFi/swift,JGiola/swift,atrick/swift,aschwaighofer/swift,xwu/swift,ahoppen/swift,rudkx/swift,parkera/swift,harlanhaskins/swift,allevato/swift,CodaFi/swift,glessard/swift,roambotics/swift,jmgc/swift,aschwaighofer/swift,stephentyrone/swift,airspeedswift/swift,airspeedswift/swift,allevato/swift,ahoppen/swift,jckarter/swift,apple/swift,airspeedswift/swift,hooman/swift,atrick/swift,aschwaighofer/swift,xwu/swift,apple/swift,aschwaighofer/swift,tkremenek/swift,nathawes/swift,tkremenek/swift,stephentyrone/swift,gregomni/swift,CodaFi/swift,stephentyrone/swift,atrick/swift,allevato/swift,benlangmuir/swift,gribozavr/swift,gribozavr/swift,JGiola/swift,nathawes/swift,glessard/swift,harlanhaskins/swift,jmgc/swift,glessard/swift,apple/swift,JGiola/swift,hooman/swift,jckarter/swift,jmgc/swift,JGiola/swift,gribozavr/swift,hooman/swift,tkremenek/swift,jmgc/swift,parkera/swift,jmgc/swift,ahoppen/swift,xwu/swift,rudkx/swift,gregomni/swift,CodaFi/swift,JGiola/swift,rudkx/swift,airspeedswift/swift,jckarter/swift,stephentyrone/swift,xwu/swift,ahoppen/swift,gribozavr/swift,gribozavr/swift,tkremenek/swift,jckarter/swift,aschwaighofer/swift,nathawes/swift,tkremenek/swift,tkremenek/swift,jckarter/swift,aschwaighofer/swift,xwu/swift,atrick/swift,xwu/swift,gribozavr/swift,allevato/swift,benlangmuir/swift,harlanhaskins/swift,roambotics/swift,glessard/swift,ahoppen/swift,hooman/swift,roambotics/swift,nathawes/swift,gregomni/swift,glessard/swift,harlanhaskins/swift,aschwaighofer/swift,apple/swift,atrick/swift,nathawes/swift,roambotics/swift,parkera/swift,parkera/swift,parkera/swift,allevato/swift,benlangmuir/swift,apple/swift,hooman/swift,jckarter/swift,tkremenek/swift,xwu/swift,harlanhaskins/swift,atrick/swift,CodaFi/swift,hooman/swift,gribozavr/swift,jckarter/swift,gribozavr/swift,rudkx/swift,glessard/swift,apple/swift,stephentyrone/swift,jmgc/swift,parkera/swift,airspeedswift/swift,CodaFi/swift,hooman/swift,rudkx/swift,allevato/swift,gregomni/swift,benlangmuir/swift,CodaFi/swift,nathawes/swift,roambotics/swift,stephentyrone/swift,roambotics/swift,parkera/swift,rudkx/swift,benlangmuir/swift,gregomni/swift,allevato/swift,benlangmuir/swift,harlanhaskins/swift,airspeedswift/swift,parkera/swift,jmgc/swift,gregomni/swift,stephentyrone/swift,ahoppen/swift