[CMake] Don't install FileCheck by default
[CMake] Don't install FileCheck by default

Not everybody can or does use the "build-script" and the build-script
can easily opt into this if it wants.

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