[ClangImporter] Note that Clang's getPresumedLoc handles invalid source locs.
[ClangImporter] Note that Clang's getPresumedLoc handles invalid source locs.

Per feedback from Ted. Comment change only.

Swift SVN r18366

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