[buildbot-script.sh] don't add symlink to clang tree
[buildbot-script.sh] don't add symlink to clang tree

We were leaving around a bit of detritus in the case where a symlink to
clang already existed under llvm

Swift SVN r20182

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