deleted file mode 100644
--- a/lib/unistr/utf16-ucs4.c
+++ /dev/null
@@ -1,53 +0,0 @@
-/* Conversion UTF-16 to UCS-4.
-   Copyright (C) 2001-2002, 2006-2007 Free Software Foundation, Inc.
-   Written by Bruno Haible <bruno@clisp.org>, 2001.
-
-   This program is free software; you can redistribute it and/or modify it
-   under the terms of the GNU Library General Public License as published
-   by the Free Software Foundation; either version 2, or (at your option)
-   any later version.
-
-   This program is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Library General Public License for more details.
-
-   You should have received a copy of the GNU Library General Public
-   License along with this program; if not, write to the Free Software
-   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
-   USA.  */
-
-#include <config.h>
-
-/* Specification.  */
-#include "utf16-ucs4.h"
-
-int
-u16_mbtouc_aux (ucs4_t *puc, const uint16_t *s, size_t n)
-{
-  uint16_t c = *s;
-
-#if CONFIG_UNICODE_SAFETY
-  if (c < 0xdc00)
-#endif
-    {
-      if (n >= 2)
-	{
-#if CONFIG_UNICODE_SAFETY
-	  if (s[1] >= 0xdc00 && s[1] < 0xe000)
-#endif
-	    {
-	      *puc = 0x10000 + ((c - 0xd800) << 10) + (s[1] - 0xdc00);
-	      return 2;
-	    }
-	  /* invalid multibyte character */
-	}
-      else
-	{
-	  /* incomplete multibyte character */
-	}
-    }
-  /* invalid multibyte character */
-  *puc = 0xfffd;
-  return 1;
-}