net: skip tests on OS X 10.8 to avoid a kernel panic

Temporary workaround until the problem is identified and a more
granular skip or fix is added.

Updates golang/go#17015

Change-Id: If3f940f9f318a3b41669fd6e870a17727d2fee82
Reviewed-on: https://go-review.googlesource.com/28587Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>

ipv6/main_test.go

+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ipv6_test
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"os/exec"
+	"runtime"
+	"strings"
+	"testing"
+)
+
+func TestMain(m *testing.M) {
+	flag.Parse()
+	if runtime.GOOS == "darwin" {
+		vers, _ := exec.Command("sw_vers", "-productVersion").Output()
+		if string(vers) == "10.8" || strings.HasPrefix(string(vers), "10.8.") {
+			fmt.Fprintf(os.Stderr, "# skipping tests on OS X 10.8 to avoid kernel panics; golang.org/issue/17015\n")
+			os.Exit(0)
+		}
+	}
+	os.Exit(m.Run())
+}