Create ltconfig.x, while we are emitting the libtool script.

ltconfig.in

diff --git a/ltconfig.in b/ltconfig.in
index d97e906..fa30691 100755
--- a/ltconfig.in
+++ b/ltconfig.in
@@ -2489,6 +2489,33 @@
 
 if test -z "$tagname"; then
   echo '### END LIBTOOL CONFIG' >> "$ofile"
+  ( cat <<EOF
+/*
+ *  DO NOT EDIT THIS FILE - it was generated by
+ *  version $LTCONFIG_VERSION of the $PACKAGE configurator.
+ *
+ *  The shell script source for creating this is in ltconfig.in.
+ *  It gets incorporated into the \`configure' script.
+ */
+#ifndef LIBTOOL_CONFIG_TEXT
+#define LIBTOOL_CONFIG_TEXT 1
+
+static const char z_ltconfig[] = "\\n\\
+EOF
+  sed -n '/### BEGIN LIBTOOL CONFIG/,/### END LIBTOOL CONFIG/p' "$ofile" | \
+  egrep -v '^[ 	]*($|#)' | \
+  sed 's/\\/\\\\/g;s/"/\\"/g;s/$/\\n\\/;$s/n\\$/n";/'
+  cat <<EOF
+
+const char* pz_ltconfig  = z_ltconfig;
+const char* pz_shell     = "$SHELL";
+const char* pz_vers      = "$VERSION";
+const char* pz_package   = "$PACKAGE";
+const char* pz_timestamp = "$TIMESTAMP";
+
+#endif /* LIBTOOL_CONFIG_TEXT */
+EOF
+  ) > ltconfig.x
 else
   echo "### END LIBTOOL TAG CONFIG: $tagname" >> "$ofile"
 fi