Runtime: Workaround for rdar://problem/18889711.
Runtime: Workaround for rdar://problem/18889711.

LLVM treats 'consume' as 'acquire' on ARM64, emitting an unnecessary barrier.

Swift SVN r23180

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