IRGen: Fix assert when applying Specialize.
IRGen: Fix assert when applying Specialize.

The callee can be AnyFunctionType, not just a concrete FunctionType.

Swift SVN r4673

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