[Runtime] Fix a warning about casting away constness in _swift_getClassOfAllocated.
[Runtime] Fix a warning about casting away constness in _swift_getClassOfAllocated.

rdar://problem/40625756
practicalswift/swift,airspeedswift/swift,shahmishal/swift,parkera/swift,apple/swift,rudkx/swift,tkremenek/swift,natecook1000/swift,gribozavr/swift,alblue/swift,shajrawi/swift,shahmishal/swift,JGiola/swift,allevato/swift,jmgc/swift,karwa/swift,rudkx/swift,benlangmuir/swift,CodaFi/swift,benlangmuir/swift,danielmartin/swift,benlangmuir/swift,natecook1000/swift,sschiau/swift,jopamer/swift,glessard/swift,rudkx/swift,amraboelela/swift,austinzheng/swift,amraboelela/swift,benlangmuir/swift,gribozavr/swift,amraboelela/swift,xedin/swift,gregomni/swift,jopamer/swift,lorentey/swift,gribozavr/swift,CodaFi/swift,JGiola/swift,jmgc/swift,allevato/swift,lorentey/swift,shajrawi/swift,harlanhaskins/swift,jopamer/swift,parkera/swift,danielmartin/swift,xwu/swift,nathawes/swift,karwa/swift,sschiau/swift,tkremenek/swift,parkera/swift,shajrawi/swift,CodaFi/swift,danielmartin/swift,sschiau/swift,roambotics/swift,hooman/swift,devincoughlin/swift,apple/swift,glessard/swift,apple/swift,aschwaighofer/swift,stephentyrone/swift,hooman/swift,hooman/swift,atrick/swift,brentdax/swift,sschiau/swift,nathawes/swift,roambotics/swift,ahoppen/swift,roambotics/swift,shahmishal/swift,jckarter/swift,atrick/swift,gribozavr/swift,allevato/swift,practicalswift/swift,aschwaighofer/swift,aschwaighofer/swift,airspeedswift/swift,airspeedswift/swift,brentdax/swift,atrick/swift,natecook1000/swift,lorentey/swift,danielmartin/swift,CodaFi/swift,brentdax/swift,amraboelela/swift,ahoppen/swift,karwa/swift,allevato/swift,jckarter/swift,airspeedswift/swift,jmgc/swift,airspeedswift/swift,sschiau/swift,aschwaighofer/swift,glessard/swift,hooman/swift,jmgc/swift,alblue/swift,hooman/swift,nathawes/swift,xwu/swift,allevato/swift,alblue/swift,austinzheng/swift,apple/swift,harlanhaskins/swift,brentdax/swift,xwu/swift,nathawes/swift,gregomni/swift,nathawes/swift,lorentey/swift,gregomni/swift,shahmishal/swift,lorentey/swift,shajrawi/swift,alblue/swift,apple/swift,jckarter/swift,jopamer/swift,jopamer/swift,harlanhaskins/swift,xwu/swift,allevato/swift,CodaFi/swift,natecook1000/swift,stephentyrone/swift,lorentey/swift,xedin/swift,karwa/swift,tkremenek/swift,roambotics/swift,sschiau/swift,glessard/swift,ahoppen/swift,shahmishal/swift,ahoppen/swift,natecook1000/swift,gribozavr/swift,allevato/swift,brentdax/swift,karwa/swift,JGiola/swift,apple/swift,CodaFi/swift,ahoppen/swift,practicalswift/swift,roambotics/swift,xedin/swift,harlanhaskins/swift,rudkx/swift,amraboelela/swift,aschwaighofer/swift,JGiola/swift,harlanhaskins/swift,alblue/swift,aschwaighofer/swift,austinzheng/swift,austinzheng/swift,gregomni/swift,roambotics/swift,CodaFi/swift,jmgc/swift,JGiola/swift,stephentyrone/swift,practicalswift/swift,devincoughlin/swift,jmgc/swift,devincoughlin/swift,harlanhaskins/swift,rudkx/swift,parkera/swift,shajrawi/swift,benlangmuir/swift,amraboelela/swift,lorentey/swift,jmgc/swift,shajrawi/swift,lorentey/swift,karwa/swift,danielmartin/swift,gribozavr/swift,devincoughlin/swift,devincoughlin/swift,practicalswift/swift,jckarter/swift,practicalswift/swift,stephentyrone/swift,jckarter/swift,hooman/swift,parkera/swift,parkera/swift,ahoppen/swift,amraboelela/swift,jckarter/swift,aschwaighofer/swift,danielmartin/swift,parkera/swift,xedin/swift,nathawes/swift,brentdax/swift,atrick/swift,stephentyrone/swift,austinzheng/swift,xedin/swift,alblue/swift,rudkx/swift,parkera/swift,tkremenek/swift,xedin/swift,gribozavr/swift,xedin/swift,shahmishal/swift,practicalswift/swift,devincoughlin/swift,shahmishal/swift,jckarter/swift,natecook1000/swift,xedin/swift,shahmishal/swift,stephentyrone/swift,practicalswift/swift,danielmartin/swift,tkremenek/swift,nathawes/swift,alblue/swift,shajrawi/swift,devincoughlin/swift,xwu/swift,karwa/swift,devincoughlin/swift,natecook1000/swift,brentdax/swift,sschiau/swift,stephentyrone/swift,harlanhaskins/swift,jopamer/swift,atrick/swift,glessard/swift,gregomni/swift,hooman/swift,tkremenek/swift,austinzheng/swift,atrick/swift,benlangmuir/swift,gribozavr/swift,airspeedswift/swift,xwu/swift,JGiola/swift,shajrawi/swift,jopamer/swift,airspeedswift/swift,karwa/swift,glessard/swift,gregomni/swift,xwu/swift,tkremenek/swift,austinzheng/swift,sschiau/swift