[windows] Enable libdispatch in the CI machine.
[windows] Enable libdispatch in the CI machine.

Enable building libdispatch (C and Swift) in the CI machine, after
LLVM/Swift/LLDB finishes building.

Enable the tests of libdispatch (C).

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