Basic: convert descriptors to `FILE *`
Basic: convert descriptors to `FILE *`

Ensure that convert the file descriptor to `FILE *` when passing the parameter
to `fs::mapped_file_region`'s constructor which takes a `FILE *`.  Repairs the
build for Windows.

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