improve error recovery when the lexer returns a tok::unknown and we're parsing an expression.
improve error recovery when the lexer returns a tok::unknown and we're parsing an expression.


Swift SVN r1739

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