Use clang++ to link swift modules/programs.
Use clang++ to link swift modules/programs.

This avoids a bunch of issues trying to correctly guess parameters
for ld for linux platforms. We know we have clang, we know it should
be able to link, so use clang.

Swift SVN r22571

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