[Constraint solver] Don't allow access to existential members that involve associated types.
[Constraint solver] Don't allow access to existential members that involve associated types.

The old type checker was performing this check, but the new type
checker was not. This really screams for the notion of 'unavailable'
declarations.


Swift SVN r5308

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