export sys.exit
update tests to use exit rather than return
ignore return value from main (actually done in prior CL)

SVN=125173
diff --git a/test/helloworld.go b/test/helloworld.go
index ae1f264..83d6b85 100644
--- a/test/helloworld.go
+++ b/test/helloworld.go
@@ -6,7 +6,6 @@
 
 package main
 
-func main() int {
+func main() {
 	print "hello, world\n";
-	return 0;
 }