Reduce standard library build times by 10s by adding a couple of type annotations to 'join'.
Reduce standard library build times by 10s by adding a couple of type annotations to 'join'.

Swift SVN r24752

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