Add an unpatched version of xz, XZ Utils, to /trunk/deps/third_party

xz/src/xz/main.h

+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       main.h
+/// \brief      Miscellaneous declarations
+//
+//  Author:     Lasse Collin
+//
+//  This file has been put into the public domain.
+//  You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+/// Possible exit status values. These are the same as used by gzip and bzip2.
+enum exit_status_type {
+        E_SUCCESS  = 0,
+        E_ERROR    = 1,
+        E_WARNING  = 2,
+};
+
+
+/// Sets the exit status after a warning or error has occurred. If new_status
+/// is E_WARNING and the old exit status was already E_ERROR, the exit
+/// status is not changed.
+extern void set_exit_status(enum exit_status_type new_status);
+
+
+/// Use E_SUCCESS instead of E_WARNING if something worth a warning occurs
+/// but nothing worth an error has occurred. This is called when --no-warn
+/// is specified.
+extern void set_exit_no_warn(void);