move things out of sys into os and runtime

R=r
OCL=28569
CL=28573
diff --git a/test/chan/fifo.go b/test/chan/fifo.go
index ad53ab6..00a297a 100644
--- a/test/chan/fifo.go
+++ b/test/chan/fifo.go
@@ -8,6 +8,8 @@
 
 package main
 
+import "os"
+
 const N = 10
 
 func AsynchFifo() {
@@ -18,7 +20,7 @@
 	for i := 0; i < N; i++ {
 		if <-ch != i {
 			print("bad receive\n");
-			sys.Exit(1);
+			os.Exit(1);
 		}
 	}
 }