SwiftShims: always define TARGET_IS_SIMULATOR
SwiftShims: always define TARGET_IS_SIMULATOR

This is used as a conditional guard rather than checked for a
definition.  Ensure that a value is always defined.  Silences a -Wundef
warning.  NFC

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