Make utils/build-toolchain compatible with Xcode new build system. (#29025)
Make utils/build-toolchain compatible with Xcode new build system. (#29025)

Xcode's new build system requires the Version entry in Info.plist to have a
particular date-based format.

Toolchains built using utils/build-toolchain now work with Xcode's new build
system.
harlanhaskins/swift,gregomni/swift,CodaFi/swift,ahoppen/swift,atrick/swift,aschwaighofer/swift,jckarter/swift,harlanhaskins/swift,jckarter/swift,glessard/swift,jckarter/swift,CodaFi/swift,jmgc/swift,xwu/swift,xwu/swift,atrick/swift,nathawes/swift,allevato/swift,jmgc/swift,allevato/swift,harlanhaskins/swift,parkera/swift,tkremenek/swift,tkremenek/swift,jckarter/swift,atrick/swift,airspeedswift/swift,gregomni/swift,CodaFi/swift,stephentyrone/swift,parkera/swift,hooman/swift,atrick/swift,tkremenek/swift,benlangmuir/swift,nathawes/swift,stephentyrone/swift,gregomni/swift,CodaFi/swift,ahoppen/swift,glessard/swift,hooman/swift,aschwaighofer/swift,jckarter/swift,hooman/swift,stephentyrone/swift,gribozavr/swift,harlanhaskins/swift,jmgc/swift,airspeedswift/swift,harlanhaskins/swift,allevato/swift,parkera/swift,roambotics/swift,parkera/swift,hooman/swift,JGiola/swift,roambotics/swift,parkera/swift,apple/swift,glessard/swift,benlangmuir/swift,gribozavr/swift,apple/swift,CodaFi/swift,gregomni/swift,xwu/swift,allevato/swift,gribozavr/swift,gribozavr/swift,jmgc/swift,JGiola/swift,harlanhaskins/swift,gribozavr/swift,tkremenek/swift,airspeedswift/swift,ahoppen/swift,allevato/swift,nathawes/swift,stephentyrone/swift,gribozavr/swift,nathawes/swift,airspeedswift/swift,roambotics/swift,aschwaighofer/swift,benlangmuir/swift,glessard/swift,jmgc/swift,stephentyrone/swift,allevato/swift,tkremenek/swift,aschwaighofer/swift,airspeedswift/swift,aschwaighofer/swift,JGiola/swift,glessard/swift,JGiola/swift,gregomni/swift,nathawes/swift,hooman/swift,roambotics/swift,atrick/swift,apple/swift,aschwaighofer/swift,hooman/swift,atrick/swift,parkera/swift,rudkx/swift,tkremenek/swift,JGiola/swift,gribozavr/swift,jmgc/swift,ahoppen/swift,parkera/swift,JGiola/swift,jckarter/swift,hooman/swift,apple/swift,gribozavr/swift,roambotics/swift,airspeedswift/swift,rudkx/swift,airspeedswift/swift,allevato/swift,rudkx/swift,xwu/swift,nathawes/swift,roambotics/swift,rudkx/swift,apple/swift,xwu/swift,xwu/swift,benlangmuir/swift,tkremenek/swift,gregomni/swift,CodaFi/swift,glessard/swift,benlangmuir/swift,CodaFi/swift,aschwaighofer/swift,rudkx/swift,stephentyrone/swift,jmgc/swift,parkera/swift,rudkx/swift,stephentyrone/swift,xwu/swift,ahoppen/swift,apple/swift,jckarter/swift,benlangmuir/swift,nathawes/swift,ahoppen/swift,harlanhaskins/swift