sync code with last improvements from OpenBSD

lib/libXt/m4/ax_define_dir.m4

@@ -0,0 +1,49 @@
+# ===========================================================================
+#       http://www.gnu.org/software/autoconf-archive/ax_define_dir.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_DEFINE_DIR(VARNAME, DIR [, DESCRIPTION])
+#
+# DESCRIPTION
+#
+#   This macro sets VARNAME to the expansion of the DIR variable, taking
+#   care of fixing up ${prefix} and such.
+#
+#   VARNAME is then offered as both an output variable and a C preprocessor
+#   symbol.
+#
+#   Example:
+#
+#     AX_DEFINE_DIR([DATADIR], [datadir], [Where data are placed to.])
+#
+# LICENSE
+#
+#   Copyright (c) 2008 Stepan Kasal <kasal@ucw.cz>
+#   Copyright (c) 2008 Andreas Schwab <schwab@suse.de>
+#   Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
+#   Copyright (c) 2008 Alexandre Oliva
+#
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved. This file is offered as-is, without any
+#   warranty.
+
+#serial 6
+
+AU_ALIAS([AC_DEFINE_DIR], [AX_DEFINE_DIR])
+AC_DEFUN([AX_DEFINE_DIR], [
+  prefix_NONE=
+  exec_prefix_NONE=
+  test "x$prefix" = xNONE && prefix_NONE=yes && prefix=$ac_default_prefix
+  test "x$exec_prefix" = xNONE && exec_prefix_NONE=yes && exec_prefix=$prefix
+dnl In Autoconf 2.60, ${datadir} refers to ${datarootdir}, which in turn
+dnl refers to ${prefix}.  Thus we have to use `eval' twice.
+  eval ax_define_dir="\"[$]$2\""
+  eval ax_define_dir="\"$ax_define_dir\""
+  AC_SUBST($1, "$ax_define_dir")
+  AC_DEFINE_UNQUOTED($1, "$ax_define_dir", [$3])
+  test "$prefix_NONE" && prefix=NONE
+  test "$exec_prefix_NONE" && exec_prefix=NONE
+])