SIL Parser: handle now-multiple attributes on AllocBoxInst
SIL Parser: handle now-multiple attributes on AllocBoxInst

JGiola/swift,atrick/swift,benlangmuir/swift,glessard/swift,glessard/swift,benlangmuir/swift,benlangmuir/swift,benlangmuir/swift,atrick/swift,atrick/swift,roambotics/swift,apple/swift,atrick/swift,atrick/swift,roambotics/swift,roambotics/swift,ahoppen/swift,glessard/swift,roambotics/swift,JGiola/swift,ahoppen/swift,glessard/swift,JGiola/swift,glessard/swift,roambotics/swift,apple/swift,benlangmuir/swift,glessard/swift,ahoppen/swift,JGiola/swift,roambotics/swift,JGiola/swift,atrick/swift,apple/swift,apple/swift,JGiola/swift,apple/swift,apple/swift,ahoppen/swift,benlangmuir/swift,ahoppen/swift,ahoppen/swift