Import xz 5.2.2 (as of svn r86089)

m4/tuklib_progname.m4

@@ -0,0 +1,25 @@
+#
+# SYNOPSIS
+#
+#   TUKLIB_PROGNAME
+#
+# DESCRIPTION
+#
+#   Put argv[0] into a global variable progname. On DOS-like systems,
+#   modify it so that it looks nice (no full path or .exe suffix).
+#
+#   This .m4 file is needed allow this module to use glibc's
+#   program_invocation_name.
+#
+# COPYING
+#
+#   Author: Lasse Collin
+#
+#   This file has been put into the public domain.
+#   You can do whatever you want with this file.
+#
+
+AC_DEFUN_ONCE([TUKLIB_PROGNAME], [
+AC_REQUIRE([TUKLIB_COMMON])
+AC_CHECK_DECLS([program_invocation_name], [], [], [#include <errno.h>])
+])dnl