Allow -o to refer to an output directory.
Allow -o to refer to an output directory.

In this case, the output filename is taken from the module name.

  swift -emit-module x/y.swift
    -> x/y.swiftmodule
  swift -emit-module x/y.swift -module-name z
    -> x/z.swiftmodule
  swift -emit-module x/y.swift -o w/
    -> w/y.swiftmodule
  swift -emit-module x/y.swift -o w/ -module-name z
    -> w/z.swiftmodule
  swift -emit-module x/y.swift -o explicit.module
    -> ./explicit.module

Swift SVN r6854

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