missed in previous giant commit

config/acx.m4

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+# Autoconf M4 include file defining utility macros for complex Canadian
+# cross builds.
+
+####
+# _NCN_TOOL_PREFIXES:  Some stuff that oughtta be done in AC_CANONICAL_SYSTEM 
+# or AC_INIT.
+# These demand that AC_CANONICAL_SYSTEM be called beforehand.
+AC_DEFUN([_NCN_TOOL_PREFIXES],
+[ncn_tool_prefix=
+test -n "$host_alias" && ncn_tool_prefix=$host_alias-
+ncn_target_tool_prefix=
+test -n "$target_alias" && ncn_target_tool_prefix=$target_alias-
+]) []dnl # _NCN_TOOL_PREFIXES
+
+####
+# NCN_CHECK_TARGET_TOOL(variable, prog-to-check-for,[value-if-not-found],[path])
+# Like AC_CHECK_TOOL, but tries a prefix of the target, not the host.
+# Code is pretty much lifted from autoconf2.53.
+
+AC_DEFUN([NCN_CHECK_TARGET_TOOL],
+[AC_REQUIRE([_NCN_TOOL_PREFIXES]) []dnl
+if test -n "$ncn_target_tool_prefix"; then
+  AC_CHECK_PROG([$1], [${ncn_target_tool_prefix}$2], 
+                [${ncn_target_tool_prefix}$2], , [$4])
+fi
+if test -z "$ac_cv_prog_$1" ; then
+  ncn_ct_$1=$$1
+  AC_CHECK_PROG([ncn_ct_$1], [$2], [$2], [$3], [$4])
+  $1=$ncn_ct_$1
+else
+  $1="$ac_cv_prog_$1"
+fi
+]) []dnl # NCN_CHECK_TARGET_TOOL
+
+
+####
+# NCN_STRICT_CHECK_TOOL(variable, prog-to-check-for,[value-if-not-found],[path])
+# Like AC_CHECK_TOOL, but requires the prefix if build!=host.
+
+AC_DEFUN([NCN_STRICT_CHECK_TOOL],
+[AC_REQUIRE([_NCN_TOOL_PREFIXES]) []dnl
+if test -n "$ncn_tool_prefix"; then
+  AC_CHECK_PROG([$1], [${ncn_tool_prefix}$2], 
+                [${ncn_tool_prefix}$2], , [$4])
+fi
+if test -z "$ac_cv_prog_$1" ; then
+  if test $build = $host ; then
+    ncn_ct_$1=$$1
+    AC_CHECK_PROG([ncn_ct_$1], [$2], [$2], [$3], [$4]) 
+    $1=$ncn_ct_$1
+  else
+    $1="$3"
+  fi
+else
+  $1="$ac_cv_prog_$1"
+fi
+]) []dnl # NCN_STRICT_CHECK_TOOL
+
+
+####
+# NCN_STRICT_CHECK_TARGET_TOOL(variable, prog-to-check-for,[value-if-not-found],[path])
+# Like NCN_CHECK_TARGET_TOOL, but requires the prefix if build!=target.
+
+AC_DEFUN([NCN_STRICT_CHECK_TARGET_TOOL],
+[AC_REQUIRE([_NCN_TOOL_PREFIXES]) []dnl
+if test -n "$ncn_target_tool_prefix"; then
+  AC_CHECK_PROG([$1], [${ncn_target_tool_prefix}$2], 
+                [${ncn_target_tool_prefix}$2], , [$4])
+fi
+if test -z "$ac_cv_prog_$1" ; then
+  if test $build = $target ; then
+    ncn_ct_$1=$$1
+    AC_CHECK_PROG([ncn_ct_$1], [$2], [$2], [$3], [$4]) 
+    $1=$ncn_ct_$1
+  else
+    $1="$3"
+  fi
+else
+  $1="$ac_cv_prog_$1"
+fi
+]) []dnl # NCN_STRICT_CHECK_TARGET_TOOL
+
+