SILGen: Fix a crash when 'x!' was able to emit into a buffer.
SILGen: Fix a crash when 'x!' was able to emit into a buffer.

Swift SVN r9040

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