test: make Frontend.vfs pass on Windows
test: make Frontend.vfs pass on Windows

Ensure that we convert the path to the correct separator for the mapping
to take effect.  This makes the last Frontend test pass on Windows.

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