[build] clobber freed objects by default in non-optimized builds
[build] clobber freed objects by default in non-optimized builds

When SWIFT_OPTIMIZED is not set, add a little extra memory debugging,
which doesn't seem to slow anything down noticeably and can be disabled
as needed.

This change only affects the CMake build because that's the only place
where SWIFT_RUNTIME_CLOBBER_FREED_OBJECTS is supported already.  We may
want to extend this to the Makefile build.

Swift SVN r13008

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