Re-enable async argument debug info test.
Re-enable async argument debug info test.

rdar//7247369

gregomni/swift,benlangmuir/swift,gregomni/swift,apple/swift,xwu/swift,glessard/swift,glessard/swift,JGiola/swift,apple/swift,ahoppen/swift,glessard/swift,gregomni/swift,glessard/swift,xwu/swift,apple/swift,roambotics/swift,ahoppen/swift,ahoppen/swift,atrick/swift,glessard/swift,atrick/swift,atrick/swift,JGiola/swift,atrick/swift,rudkx/swift,ahoppen/swift,JGiola/swift,benlangmuir/swift,rudkx/swift,gregomni/swift,roambotics/swift,xwu/swift,JGiola/swift,xwu/swift,atrick/swift,benlangmuir/swift,roambotics/swift,xwu/swift,roambotics/swift,xwu/swift,roambotics/swift,benlangmuir/swift,xwu/swift,apple/swift,benlangmuir/swift,glessard/swift,JGiola/swift,rudkx/swift,atrick/swift,apple/swift,ahoppen/swift,ahoppen/swift,roambotics/swift,rudkx/swift,rudkx/swift,gregomni/swift,apple/swift,benlangmuir/swift,JGiola/swift,gregomni/swift,rudkx/swift