net, internal/poll: enable ListenMulticastUDP on solaris

Fixes #20898.

Change-Id: Ib3a8da34851d8b3681a6802e509fe712d6982df2
Reviewed-on: https://go-review.googlesource.com/47450
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Avelino <t@avelino.xxx>

src/internal/poll/sockoptip.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 darwin dragonfly freebsd linux netbsd openbsd windows
+// +build darwin dragonfly freebsd linux netbsd openbsd solaris windows
 
 package poll
 

src/net/sockoptip_bsd.go → src/net/sockoptip_bsdvar.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 darwin dragonfly freebsd netbsd openbsd
+// +build darwin dragonfly freebsd netbsd openbsd solaris
 
 package net
 

src/net/sockoptip_posix.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 darwin dragonfly freebsd linux netbsd openbsd windows
+// +build darwin dragonfly freebsd linux netbsd openbsd solaris windows
 
 package net
 

src/net/sockoptip_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 nacl solaris
+// +build nacl
 
 package net