[stdlib] add SingleGenerator
[stdlib] add SingleGenerator

Should be useful for T? and SequenceOfOne<T>

Swift SVN r13968

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