ssh/test: skip test to fix build on solaris and aix

Change-Id: I734bf1f709a259889eeb9243079edb90d6751f67
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/170677
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>

ssh/test/dial_unix_test.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 !windows
+// +build !windows,!solaris,!aix
 
 package test
 

ssh/test/session_test.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 !windows
+// +build !windows,!solaris,!aix
 
 package test