[stdlib] Avoid storing NULL into a Builtin.RawPointer. (#2236)
[stdlib] Avoid storing NULL into a Builtin.RawPointer. (#2236)

Found by Dmitri.
harlanhaskins/swift,shahmishal/swift,parkera/swift,gribozavr/swift,roambotics/swift,uasys/swift,ken0nek/swift,aschwaighofer/swift,aschwaighofer/swift,manavgabhawala/swift,hooman/swift,IngmarStein/swift,jopamer/swift,amraboelela/swift,xwu/swift,practicalswift/swift,IngmarStein/swift,xedin/swift,jckarter/swift,frootloops/swift,milseman/swift,stephentyrone/swift,xedin/swift,ben-ng/swift,huonw/swift,gribozavr/swift,allevato/swift,ken0nek/swift,jtbandes/swift,OscarSwanros/swift,aschwaighofer/swift,JGiola/swift,gottesmm/swift,felix91gr/swift,kstaring/swift,xwu/swift,xedin/swift,hooman/swift,CodaFi/swift,OscarSwanros/swift,JaSpa/swift,harlanhaskins/swift,tkremenek/swift,arvedviehweger/swift,alblue/swift,tjw/swift,gregomni/swift,ahoppen/swift,sschiau/swift,calebd/swift,arvedviehweger/swift,practicalswift/swift,swiftix/swift,jopamer/swift,stephentyrone/swift,allevato/swift,harlanhaskins/swift,alblue/swift,ahoppen/swift,gmilos/swift,jckarter/swift,dreamsxin/swift,arvedviehweger/swift,danielmartin/swift,rudkx/swift,parkera/swift,manavgabhawala/swift,return/swift,atrick/swift,austinzheng/swift,austinzheng/swift,airspeedswift/swift,austinzheng/swift,shajrawi/swift,benlangmuir/swift,IngmarStein/swift,swiftix/swift,djwbrown/swift,lorentey/swift,benlangmuir/swift,lorentey/swift,brentdax/swift,shajrawi/swift,jtbandes/swift,gmilos/swift,codestergit/swift,allevato/swift,calebd/swift,therealbnut/swift,johnno1962d/swift,ahoppen/swift,glessard/swift,modocache/swift,JGiola/swift,kperryua/swift,sschiau/swift,arvedviehweger/swift,tinysun212/swift-windows,therealbnut/swift,OscarSwanros/swift,gribozavr/swift,glessard/swift,JaSpa/swift,aschwaighofer/swift,jckarter/swift,natecook1000/swift,return/swift,hughbe/swift,milseman/swift,codestergit/swift,ken0nek/swift,practicalswift/swift,OscarSwanros/swift,aschwaighofer/swift,tjw/swift,sschiau/swift,natecook1000/swift,hooman/swift,tinysun212/swift-windows,natecook1000/swift,tkremenek/swift,roambotics/swift,modocache/swift,OscarSwanros/swift,atrick/swift,devincoughlin/swift,xedin/swift,codestergit/swift,glessard/swift,tkremenek/swift,CodaFi/swift,karwa/swift,parkera/swift,brentdax/swift,shahmishal/swift,russbishop/swift,modocache/swift,glessard/swift,jckarter/swift,benlangmuir/swift,atrick/swift,practicalswift/swift,jopamer/swift,codestergit/swift,parkera/swift,amraboelela/swift,Jnosh/swift,deyton/swift,jtbandes/swift,karwa/swift,austinzheng/swift,lorentey/swift,zisko/swift,shahmishal/swift,hughbe/swift,practicalswift/swift,apple/swift,arvedviehweger/swift,gottesmm/swift,alblue/swift,xwu/swift,deyton/swift,gregomni/swift,practicalswift/swift,apple/swift,tjw/swift,devincoughlin/swift,gregomni/swift,JaSpa/swift,gregomni/swift,huonw/swift,JaSpa/swift,swiftix/swift,gribozavr/swift,sschiau/swift,shahmishal/swift,natecook1000/swift,ken0nek/swift,austinzheng/swift,uasys/swift,aschwaighofer/swift,felix91gr/swift,johnno1962d/swift,benlangmuir/swift,aschwaighofer/swift,xwu/swift,russbishop/swift,tinysun212/swift-windows,russbishop/swift,apple/swift,apple/swift,IngmarStein/swift,manavgabhawala/swift,gribozavr/swift,airspeedswift/swift,gribozavr/swift,Jnosh/swift,natecook1000/swift,devincoughlin/swift,CodaFi/swift,bitjammer/swift,IngmarStein/swift,devincoughlin/swift,uasys/swift,nathawes/swift,shahmishal/swift,harlanhaskins/swift,atrick/swift,felix91gr/swift,amraboelela/swift,xedin/swift,felix91gr/swift,huonw/swift,arvedviehweger/swift,swiftix/swift,gmilos/swift,therealbnut/swift,gribozavr/swift,nathawes/swift,JaSpa/swift,tinysun212/swift-windows,milseman/swift,frootloops/swift,rudkx/swift,stephentyrone/swift,ken0nek/swift,roambotics/swift,zisko/swift,jckarter/swift,CodaFi/swift,kperryua/swift,IngmarStein/swift,jtbandes/swift,karwa/swift,sschiau/swift,brentdax/swift,ben-ng/swift,gmilos/swift,devincoughlin/swift,jtbandes/swift,modocache/swift,johnno1962d/swift,parkera/swift,kperryua/swift,devincoughlin/swift,jopamer/swift,dreamsxin/swift,lorentey/swift,Jnosh/swift,lorentey/swift,danielmartin/swift,shajrawi/swift,kstaring/swift,manavgabhawala/swift,sschiau/swift,practicalswift/swift,gottesmm/swift,jckarter/swift,jmgc/swift,codestergit/swift,russbishop/swift,apple/swift,johnno1962d/swift,shajrawi/swift,hooman/swift,ben-ng/swift,atrick/swift,sschiau/swift,brentdax/swift,gottesmm/swift,deyton/swift,Jnosh/swift,harlanhaskins/swift,ahoppen/swift,bitjammer/swift,tardieu/swift,ken0nek/swift,russbishop/swift,kstaring/swift,tardieu/swift,tjw/swift,swiftix/swift,gregomni/swift,tinysun212/swift-windows,danielmartin/swift,uasys/swift,nathawes/swift,deyton/swift,tjw/swift,return/swift,glessard/swift,stephentyrone/swift,manavgabhawala/swift,tkremenek/swift,felix91gr/swift,bitjammer/swift,bitjammer/swift,gmilos/swift,bitjammer/swift,CodaFi/swift,ahoppen/swift,frootloops/swift,Jnosh/swift,tardieu/swift,karwa/swift,xedin/swift,kstaring/swift,djwbrown/swift,austinzheng/swift,huonw/swift,airspeedswift/swift,tardieu/swift,gmilos/swift,zisko/swift,alblue/swift,amraboelela/swift,therealbnut/swift,allevato/swift,jmgc/swift,modoc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