Add spare bit mask constants for i386 and ARM.
Add spare bit mask constants for i386 and ARM.

Heap objects are pointer-aligned, so we still have spare bits in heap object pointers even on these platforms.

Swift SVN r18988

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