validation-tests: define the MSVC runtime to use
validation-tests: define the MSVC runtime to use

This variable is needed to run the validation test suite on Windows.

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