Don't barf in BoundGenericType::getSubstitutions when a protocol type conforms to a protocol.
Don't barf in BoundGenericType::getSubstitutions when a protocol type conforms to a protocol.

This comes through as UncheckedConforms, and we expect a null conformance, so pass it through. DaveA's incoming patches will exercise this. Fixes rdar://problem/18992875.

Swift SVN r23377

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