Minor clean-up. Invoke SILType::subst only when needed.
Minor clean-up. Invoke SILType::subst only when needed.

Swift SVN r23659

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