Add a defensive assertion to make sure the Clang importer doesn't return null imported modules
Add a defensive assertion to make sure the Clang importer doesn't return null imported modules


Swift SVN r18687

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