unix: add Major, Minor and Mkdev functions on Solaris

Add Major, Minor and Mkdev functions for converting device numbers to
their major/minor components and vice versa.

Use the respective functions provided by the Solaris libc instead of
reimplementing them.

Test the conversion function with some well-known static device numbers
for devices which should be present on any Solaris system.

Re-generated files on OpenIndiana Hipster 2017.04 (SunOS 5.11) which
also added some previously missing error constants.

Change-Id: Ief9ea973d91c24956571eb8fafc8a4525b0f5b90
Reviewed-on: https://go-review.googlesource.com/64390
Reviewed-by: Ian Lance Taylor <iant@golang.org>

unix/dev_solaris_test.go

@@ -0,0 +1,49 @@
+// Copyright 2017 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 unix_test
+
+import (
+	"fmt"
+	"testing"
+
+	"golang.org/x/sys/unix"
+)
+
+func TestDevices(t *testing.T) {
+	testCases := []struct {
+		path  string
+		major uint32
+		minor uint32
+	}{
+		// Well-known major/minor numbers on OpenSolaris according to
+		// /etc/name_to_major
+		{"/dev/zero", 134, 12},
+		{"/dev/null", 134, 2},
+		{"/dev/ptyp0", 172, 0},
+		{"/dev/ttyp0", 175, 0},
+		{"/dev/ttyp1", 175, 1},
+	}
+	for _, tc := range testCases {
+		t.Run(fmt.Sprintf("%s %v:%v", tc.path, tc.major, tc.minor), func(t *testing.T) {
+			var stat unix.Stat_t
+			err := unix.Stat(tc.path, &stat)
+			if err != nil {
+				t.Errorf("failed to stat device: %v", err)
+				return
+			}
+
+			dev := uint64(stat.Rdev)
+			if unix.Major(dev) != tc.major {
+				t.Errorf("for %s Major(%#x) == %d, want %d", tc.path, dev, unix.Major(dev), tc.major)
+			}
+			if unix.Minor(dev) != tc.minor {
+				t.Errorf("for %s Minor(%#x) == %d, want %d", tc.path, dev, unix.Minor(dev), tc.minor)
+			}
+			if unix.Mkdev(tc.major, tc.minor) != dev {
+				t.Errorf("for %s Mkdev(%d, %d) == %#x, want %#x", tc.path, tc.major, tc.minor, unix.Mkdev(tc.major, tc.minor), dev)
+			}
+		})
+	}
+}