Allow substitution to walk into reference storage types.
Allow substitution to walk into reference storage types.

For now, don't allow transforms to work on SILFunctionTypes.

Swift SVN r10066

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