libgo patch committed: Support stat and device numbers on AIX

[Ian Lance Taylor]

This patch by Tony Reix adds support for stat and device numbers on
AIX.  Bootstrapped and ran Go tests on x86_64-pc-linux-gnu.  Committed
to  mainline.

Ian

Index: gcc/go/gofrontend/MERGE
===================================================================
--- gcc/go/gofrontend/MERGE     (revision 256794)
+++ gcc/go/gofrontend/MERGE     (working copy)
@@ -1,4 +1,4 @@
-ca805b704fc141d7ad61f8fcd3badbaa04b7e363
+3ea7fc3b918210e7248dbc51d90af20639dc4167
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.
Index: libgo/go/archive/tar/stat_actime1.go
===================================================================
--- libgo/go/archive/tar/stat_actime1.go        (revision 256593)
+++ libgo/go/archive/tar/stat_actime1.go        (working copy)
@@ -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 linux dragonfly openbsd solaris
+// +build aix linux dragonfly openbsd solaris
 
 package tar
 
Index: libgo/go/archive/tar/stat_unix.go
===================================================================
--- libgo/go/archive/tar/stat_unix.go   (revision 256593)
+++ libgo/go/archive/tar/stat_unix.go   (working copy)
@@ -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 linux darwin dragonfly freebsd openbsd netbsd solaris
+// +build aix linux darwin dragonfly freebsd openbsd netbsd solaris
 
 package tar
 
@@ -54,6 +54,16 @@ func statUnix(fi os.FileInfo, h *Header)
        if h.Typeflag == TypeChar || h.Typeflag == TypeBlock {
                dev := uint64(sys.Rdev) // May be int32 or uint32
                switch runtime.GOOS {
+               case "aix":
+                       var major, minor uint32
+                       if runtime.GOARCH == "ppc64" {
+                               major = uint32((dev & 0x3fffffff00000000) >> 32)
+                               minor = uint32((dev & 0x00000000ffffffff) >> 0)
+                       } else {
+                               major = uint32((dev >> 16) & 0xffff)
+                               minor = uint32(dev & 0xffff)
+                       }
+                       h.Devmajor, h.Devminor = int64(major), int64(minor)
                case "linux":
                        // Copied from golang.org/x/sys/unix/dev_linux.go.
                        major := uint32((dev & 0x00000000000fff00) >> 8)