Update SIL.rst for the change to the checked_cast instructions.
Update SIL.rst for the change to the checked_cast instructions.

I still owe an update for the checked_cast_addr instructions.

Swift SVN r19057

mightydeveloper/swift,CodaFi/swift,harlanhaskins/swift,apple/swift,rudkx/swift,rudkx/swift,LeoShimonaka/swift,dreamsxin/swift,kentya6/swift,tinysun212/swift-windows,devincoughlin/swift,kentya6/swift,gregomni/swift,JaSpa/swift,shajrawi/swift,SwiftAndroid/swift,gribozavr/swift,glessard/swift,codestergit/swift,IngmarStein/swift,sdulal/swift,dduan/swift,SwiftAndroid/swift,harlanhaskins/swift,huonw/swift,swiftix/swift.old,kperryua/swift,gmilos/swift,atrick/swift,tjw/swift,ahoppen/swift,KrishMunot/swift,danielmartin/swift,tjw/swift,jckarter/swift,CodaFi/swift,dduan/swift,roambotics/swift,ben-ng/swift,jopamer/swift,aschwaighofer/swift,gottesmm/swift,cbrentharris/swift,jckarter/swift,mightydeveloper/swift,Ivacker/swift,djwbrown/swift,shahmishal/swift,gribozavr/swift,swiftix/swift.old,kusl/swift,practicalswift/swift,lorentey/swift,sdulal/swift,deyton/swift,austinzheng/swift,benlangmuir/swift,deyton/swift,djwbrown/swift,sschiau/swift,felix91gr/swift,deyton/swift,johnno1962d/swift,arvedviehweger/swift,alblue/swift,xedin/swift,calebd/swift,shajrawi/swift,glessard/swift,kusl/swift,Jnosh/swift,xedin/swift,return/swift,kusl/swift,dduan/swift,tjw/swift,huonw/swift,huonw/swift,LeoShimonaka/swift,milseman/swift,cbrentharris/swift,Jnosh/swift,ahoppen/swift,allevato/swift,manavgabhawala/swift,dduan/swift,swiftix/swift,alblue/swift,adrfer/swift,manavgabhawala/swift,tkremenek/swift,harlanhaskins/swift,ken0nek/swift,deyton/swift,modocache/swift,kusl/swift,gottesmm/swift,jtbandes/swift,Ivacker/swift,jtbandes/swift,allevato/swift,djwbrown/swift,ben-ng/swift,Jnosh/swift,tardieu/swift,MukeshKumarS/Swift,glessard/swift,stephentyrone/swift,tjw/swift,karwa/swift,natecook1000/swift,lorentey/swift,glessard/swift,gmilos/swift,allevato/swift,gmilos/swift,practicalswift/swift,jtbandes/swift,CodaFi/swift,sschiau/swift,kusl/swift,ahoppen/swift,dduan/swift,JGiola/swift,arvedviehweger/swift,modocache/swift,jopamer/swift,harlanhaskins/swift,zisko/swift,manavgabhawala/swift,milseman/swift,alblue/swift,johnno1962d/swift,adrfer/swift,LeoShimonaka/swift,brentdax/swift,frootloops/swift,stephentyrone/swift,IngmarStein/swift,russbishop/swift,zisko/swift,tinysun212/swift-windows,gregomni/swift,xwu/swift,lorentey/swift,Ivacker/swift,jmgc/swift,SwiftAndroid/swift,huonw/swift,harlanhaskins/swift,devincoughlin/swift,gottesmm/swift,milseman/swift,arvedviehweger/swift,sschiau/swift,djwbrown/swift,cbrentharris/swift,CodaFi/swift,uasys/swift,jopamer/swift,slavapestov/swift,cbrentharris/swift,gmilos/swift,gribozavr/swift,mightydeveloper/swift,IngmarStein/swift,bitjammer/swift,brentdax/swift,glessard/swift,shahmishal/swift,codestergit/swift,natecook1000/swift,benlangmuir/swift,russbishop/swift,LeoShimonaka/swift,MukeshKumarS/Swift,JaSpa/swift,gribozavr/swift,deyton/swift,IngmarStein/swift,codestergit/swift,hooman/swift,tardieu/swift,bitjammer/swift,stephentyrone/swift,kentya6/swift,karwa/swift,mightydeveloper/swift,ben-ng/swift,slavapestov/swift,hooman/swift,LeoShimonaka/swift,uasys/swift,rudkx/swift,nathawes/swift,jmgc/swift,gribozavr/swift,atrick/swift,ahoppen/swift,hughbe/swift,MukeshKumarS/Swift,modocache/swift,devincoughlin/swift,brentdax/swift,ahoppen/swift,allevato/swift,russbishop/swift,dreamsxin/swift,Ivacker/swift,tinysun212/swift-windows,parkera/swift,jckarter/swift,arvedviehweger/swift,KrishMunot/swift,uasys/swift,gottesmm/swift,parkera/swift,amraboelela/swift,milseman/swift,JaSpa/swift,frootloops/swift,khizkhiz/swift,mightydeveloper/swift,uasys/swift,kstaring/swift,tardieu/swift,karwa/swift,xwu/swift,parkera/swift,russbishop/swift,airspeedswift/swift,modocache/swift,swiftix/swift.old,kperryua/swift,ken0nek/swift,milseman/swift,jmgc/swift,apple/swift,natecook1000/swift,MukeshKumarS/Swift,zisko/swift,austinzheng/swift,frootloops/swift,danielmartin/swift,nathawes/swift,roambotics/swift,return/swift,lorentey/swift,kperryua/swift,jckarter/swift,return/swift,manavgabhawala/swift,johnno1962d/swift,Ivacker/swift,khizkhiz/swift,JaSpa/swift,danielmartin/swift,gmilos/swift,gottesmm/swift,airspeedswift/swift,amraboelela/swift,nathawes/swift,frootloops/swift,jmgc/swift,aschwaighofer/swift,parkera/swift,ben-ng/swift,parkera/swift,devincoughlin/swift,ahoppen/swift,devincoughlin/swift,kperryua/swift,rudkx/swift,amraboelela/swift,JaSpa/swift,kentya6/swift,therealbnut/swift,CodaFi/swift,harlanhaskins/swift,khizkhiz/swift,IngmarStein/swift,brentdax/swift,arvedviehweger/swift,tkremenek/swift,swiftix/swift,xwu/swift,devincoughlin/swift,parkera/swift,cbrentharris/swift,roambotics/swift,devincoughlin/swift,practicalswift/swift,khizkhiz/swift,therealbnut/swift,bitjammer/swift,ben-ng/swift,return/swift,amraboelela/swift,tjw/swift,calebd/swift,danielmartin/swift,codestergit/swift,apple/swift,russbishop/swift,xedin/swift,JGiola/swift,felix91gr/swift,allevato/swift,mightydeveloper/swift,ken0nek/swift,alblue/swift,kusl/swift,nathawes/swift,stephentyrone/swift,lorentey/swift,mightydeveloper/swift,kstaring/swift,huonw/swift,amraboelela/swift,kstaring/swift,jopamer/swift,tinysun212/swift-windows,gottesmm/swift,jopamer/swift,tardieu/swift,djwbrown/swift,tkremenek/swift,hooman/swift,shahmishal/swift,benlangmuir/swift,therealbnut/swift,karwa/swift,russbishop/swift,SwiftAndroid/swift,ben-ng/swift,shajrawi/swift,zisko/swift,calebd/swift,sschiau/swift,therealbnut/swift,brentdax/swift,hooman/swift,khizkhiz/swift,Ivacker/swift,kstaring/swift,sschiau/swift,natecook1000/swift,modocache/swift,return/swift,khizkhiz/swift,emilstahl/swift,bitjammer/swift,atrick/swift,alblue/swift,LeoShimonaka/swift,shajrawi/swift,KrishMunot/swift,sdulal/swift,nathawes/swift,jmgc/swift,hughbe/swift,sdulal/swift,kperryua/swift,johnno1962d/swift,swiftix/swift,bitjammer/swift,kentya6/swift,CodaFi/swift,uasys/swift,milseman/swift,sdulal/swift,slavapestov/swift,OscarSwanros/swift,swiftix/swift.old,parkera/swift,roambotics/swift,codestergit/swift,jtbandes/swift,cbrentharris/swift,atrick/swift,cbrentharris/swift,therealbnut/swift,danielmartin/swift,stephentyrone/swift,bitjammer/swift,benlangmuir/swift,OscarSwanros/swift,aschwaighofer/swift,return/swift,shahmishal/swift,swiftix/swift,xedin/swift,aschwaighofer/swift,frootloops/swift,stephentyrone/swift,ken0nek/swift,airspeedswift/swift,kentya6/swift,johnno1962d/swift,emilstahl/swift,aschwaighofer/swift,Jnosh/swift,xwu/swift,russbishop/swift,gribozavr/swift,felix91gr/swift,calebd/swift,KrishMunot/swift,hughbe/swift,tkremenek/swift,rudkx/swift,apple/swift,calebd/swift,austinzheng/swift,therealbnut/swift,karwa/swift,shajrawi/swift,adrfer/swift,xwu/swift,gregomni/swift,aschwaighofer/swift,adrfer/swift,KrishMunot/swift,lorentey/swift,zisko/swift,KrishMunot/swift,tardieu/swift,kstaring/swift,tkremenek/swift,parkera/swift,shahmishal/swift,swiftix/swift.old,jmgc/swift,gregomni/swift,slavapestov/swift,shahmishal/swift,OscarSwanros/swift,xedin/swift,uasys/swift,SwiftAndroid/swift,zisko/swift,dduan/swift,OscarSwanros/swift,jopamer/swift,alblue/swift,IngmarStein/swift,swiftix/swift.old,frootloops/swift,KrishMunot/swift,tkremenek/swift,Ivacker/swift,natecook1000/swift,felix91gr/swift,karwa/swift,OscarSwanros/swift,MukeshKumarS/Swift,amraboelela/swift,allevato/swift,sdulal/swift,harlanhaskins/swift,khizkhiz/swift,johnno1962d/swift,kstaring/swift,sdulal/swift,hooman/swift,felix91gr/swift,amraboelela/swift,xwu/swift,MukeshKumarS/Swift,Jnosh/swift,arvedviehweger/swift,tjw/swift,jtbandes/swift,practicalswift/swift,JGiola/swift,adrfer/swift,codestergit/swift,jckarter/swift,gribozavr/swift,airspeedswift/swift,JGiola/swift,codestergit/swift,nathawes/swift,swiftix/swift.old,sschiau/swift,airspeedswift/swift,Ivacker/swift,austinzheng/swift,SwiftAndroid/swift,tardieu/swift,gregomni/swift,OscarSwanros/swift,slavapestov/swift,felix91gr/swift,SwiftAndroid/swift,MukeshKumarS/Swift,swiftix/swift,hughbe/swift,kusl/swift,natecook1000/swift,kentya6/swift,emilstahl/swift,austinzheng/swift,shajrawi/swift,rudkx/swift,shahmishal/swift,shahmishal/swift,practicalswift/swift,devincoughlin/swift,calebd/swift,sdulal/swift,gottesmm/swift,gribozavr/swift,sschiau/swift,tjw/swift,ken0nek/swift,airspeedswift/swift,practicalswift/swift,tinysun212/swift-windows,emilstahl/swift,shajrawi/swift,tinysun212/swift-windows,deyton/swift,natecook1000/swift,tkremenek/swift,gmilos/swift,djwbrown/swift,jopamer/swift,Jnosh/swift,ken0nek/swift,brentdax/swift,aschwaighofer/swift,JaSpa/swift,glessard/swift,roambotics/swift,zisko/swift,calebd/swift,gmilos/swift,JaSpa/swift,djwbrown/swift,mightydeveloper/swift,CodaFi/swift,shajrawi/swift,bitjammer/swift,lorentey/swift,benlangmuir/swift,therealbnut/swift,kentya6/swift,cbrentharris/swift,jtbandes/swift,allevato/swift,manavgabhawala/swift,hughbe/swift,swiftix/swift,xedin/swift,modocache/swift,slavapestov/swift,karwa/swift,austinzheng/swift,lorentey/swift,LeoShimonaka/swift,austinzheng/swift,IngmarStein/swift,hooman/swift,stephentyrone/swift,deyton/swift,ken0nek/swift,kusl/swift,huonw/swift,arvedviehweger/swift,hooman/swift,practicalswift/swift,OscarSwanros/swift,apple/swift,jckarter/swift,manavgabhawala/swift,brentdax/swift,LeoShimonaka/swift,kperryua/swift,xedin/swift,atrick/swift,swiftix/swift,kperryua/swift,tardieu/swift,emilstahl/swift,modocache/swift,swiftix/swift.old,hughbe/swift,alblue/swift,gregomni/swift,hughbe/swift,JGiola/swift,adrfer/swift,nathawes/swift,ben-ng/swift,airspeedswift/swift,atrick/swift,frootloops/swift,manavgabhawala/swift,kstaring/swift,Jnosh/swift,benlangmuir/swift,sschiau/swift,roambotics/swift,emilstahl/swift,xwu/swift,adrfer/swift,felix91gr/swift,danielmartin/swift,emilstahl/swift,jtbandes/swift,danielmartin/swift,dduan/swift,milseman/swift,practicalswift/swift,uasys/swift,JGiola/swift,return/swift,huonw/swift,tinysun212/swift-windows,xedin/swift,johnno1962d/swift,apple/swift,emilstahl/swift,slavapestov/swift,jmgc/swift,karwa/swift,jckarter/swift