go.net/ipv6: add stubs for nacl build

LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/98440046

ipv6/control_rfc3542_stub.go

diff --git a/ipv6/control_rfc3542_stub.go b/ipv6/control_rfc3542_stub.go
index 214142e..538ffec 100644
--- a/ipv6/control_rfc3542_stub.go
+++ b/ipv6/control_rfc3542_stub.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build plan9 solaris
+// +build nacl plan9 solaris
 
 package ipv6
 

ipv6/dgramopt_stub.go

diff --git a/ipv6/dgramopt_stub.go b/ipv6/dgramopt_stub.go
index 6d73fcd..a39bd71 100644
--- a/ipv6/dgramopt_stub.go
+++ b/ipv6/dgramopt_stub.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build plan9 solaris
+// +build nacl plan9 solaris
 
 package ipv6
 

ipv6/genericopt_stub.go

diff --git a/ipv6/genericopt_stub.go b/ipv6/genericopt_stub.go
index 1f8df1b..8871df9 100644
--- a/ipv6/genericopt_stub.go
+++ b/ipv6/genericopt_stub.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build plan9 solaris
+// +build nacl plan9 solaris
 
 package ipv6
 

ipv6/helper_stub.go

diff --git a/ipv6/helper_stub.go b/ipv6/helper_stub.go
index d6e643b..1864ba0 100644
--- a/ipv6/helper_stub.go
+++ b/ipv6/helper_stub.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build plan9 solaris
+// +build nacl plan9 solaris
 
 package ipv6
 

ipv6/icmp_stub.go

diff --git a/ipv6/icmp_stub.go b/ipv6/icmp_stub.go
index 177e9cb..9588715 100644
--- a/ipv6/icmp_stub.go
+++ b/ipv6/icmp_stub.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build plan9 solaris
+// +build nacl plan9 solaris
 
 package ipv6
 

ipv6/payload_cmsg.go

diff --git a/ipv6/payload_cmsg.go b/ipv6/payload_cmsg.go
index 658467a..8e90d32 100644
--- a/ipv6/payload_cmsg.go
+++ b/ipv6/payload_cmsg.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !plan9,!windows
+// +build !nacl,!plan9,!windows
 
 package ipv6
 

ipv6/payload_noncmsg.go

diff --git a/ipv6/payload_noncmsg.go b/ipv6/payload_noncmsg.go
index dd0630a..499204d 100644
--- a/ipv6/payload_noncmsg.go
+++ b/ipv6/payload_noncmsg.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build plan9 windows
+// +build nacl plan9 windows
 
 package ipv6
 

ipv6/sockopt_rfc3542_stub.go

diff --git a/ipv6/sockopt_rfc3542_stub.go b/ipv6/sockopt_rfc3542_stub.go
index 7d7eae5..03aa43b 100644
--- a/ipv6/sockopt_rfc3542_stub.go
+++ b/ipv6/sockopt_rfc3542_stub.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build plan9 solaris
+// +build nacl plan9 solaris
 
 package ipv6