test: skip SIGCHLD test on Plan 9

LGTM=bradfitz
R=jas, mikioh.mikioh, bradfitz
CC=golang-codereviews
https://golang.org/cl/51200045

diff --git a/test/sigchld.go b/test/sigchld.go
index a60d28deaab3b049ee5e7fb2adacab8d2ce09fb2..38437e5522b26bd427bfc1ceef5cd9035117a352 100644 (file)
--- a/test/sigchld.go
+++ b/test/sigchld.go
@@ -1,4 +1,4 @@
-// +build !windows
+// +build !plan9,!windows
 // cmpout
 
 // Copyright 2009 The Go Authors. All rights reserved.