Runtime: Don't double-free existential containers when destroying them generically.
Runtime: Don't double-free existential containers when destroying them generically.

Fixes <rdar://problem/16384633>.

Swift SVN r15338

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