Swift SIL: fix `BeginAccessInst.endInstructions`
Swift SIL: fix `BeginAccessInst.endInstructions`

apple/swift,roambotics/swift,roambotics/swift,apple/swift,benlangmuir/swift,glessard/swift,apple/swift,roambotics/swift,glessard/swift,glessard/swift,glessard/swift,glessard/swift,benlangmuir/swift,apple/swift,benlangmuir/swift,benlangmuir/swift,apple/swift,roambotics/swift,benlangmuir/swift,benlangmuir/swift,roambotics/swift,apple/swift,glessard/swift,roambotics/swift