unix: add Statx on Linux

statx(2) allows to get enhanced file status information (not currently
available through the existing stat syscalls), lightweight stat,
heavyweight stat. The Statx_t type used by Statx has consistent field
sizes on all arches (with year-2038-capable timestamps) and is closer to
the BSD implementation of Stat_t.

See http://man7.org/linux/man-pages/man2/statx.2.html for details. The
syscall was added in Linux kernel 4.11.

See https://github.com/tklauser/statx for an example of how this
function and types can be used to report stat(1)-like file status
information.

Change-Id: I9e9642b5b42a393f94fd532453888ce9ba4f0003
Reviewed-on: https://go-review.googlesource.com/87555
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/unix/zerrors_linux_386.go b/unix/zerrors_linux_386.go
index 8947248..4fba476 100644
--- a/unix/zerrors_linux_386.go
+++ b/unix/zerrors_linux_386.go
@@ -1638,6 +1638,27 @@
 	SPLICE_F_MORE                        = 0x4
 	SPLICE_F_MOVE                        = 0x1
 	SPLICE_F_NONBLOCK                    = 0x2
+	STATX_ALL                            = 0xfff
+	STATX_ATIME                          = 0x20
+	STATX_ATTR_APPEND                    = 0x20
+	STATX_ATTR_AUTOMOUNT                 = 0x1000
+	STATX_ATTR_COMPRESSED                = 0x4
+	STATX_ATTR_ENCRYPTED                 = 0x800
+	STATX_ATTR_IMMUTABLE                 = 0x10
+	STATX_ATTR_NODUMP                    = 0x40
+	STATX_BASIC_STATS                    = 0x7ff
+	STATX_BLOCKS                         = 0x400
+	STATX_BTIME                          = 0x800
+	STATX_CTIME                          = 0x80
+	STATX_GID                            = 0x10
+	STATX_INO                            = 0x100
+	STATX_MODE                           = 0x2
+	STATX_MTIME                          = 0x40
+	STATX_NLINK                          = 0x4
+	STATX_SIZE                           = 0x200
+	STATX_TYPE                           = 0x1
+	STATX_UID                            = 0x8
+	STATX__RESERVED                      = 0x80000000
 	S_BLKSIZE                            = 0x200
 	S_IEXEC                              = 0x40
 	S_IFBLK                              = 0x6000