[Parse] Use a clearer condition for inactive #if blocks.
[Parse] Use a clearer condition for inactive #if blocks.

Fix-up to r25567 suggested by Denis. No functionality change.

Swift SVN r25601

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