Update diagnostic to say 'guard' instead of 'require'.
Update diagnostic to say 'guard' instead of 'require'.

Swift SVN r28273

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