remove support for non-ANSI compilation

*** 18,46 ****
   * information: Portions Copyright [yyyy] [name of copyright owner]
   *
   * CDDL HEADER END
   */
  /*
   * Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  
  #ifndef _ICONV_H
  #define _ICONV_H
  
- #pragma ident   "%Z%%M% %I%     %E% SMI"
- 
  #include <sys/feature_tests.h>
  #include <sys/types.h>
  
  #ifdef  __cplusplus
  extern "C" {
  #endif
  
  typedef struct _iconv_info *iconv_t;
  
- #if defined(__STDC__)
  extern iconv_t  iconv_open(const char *, const char *);
  #ifdef _XPG6
  extern size_t   iconv(iconv_t, char **_RESTRICT_KYWD,
                  size_t *_RESTRICT_KYWD, char **_RESTRICT_KYWD,
                  size_t *_RESTRICT_KYWD);
--- 18,45 ----
   * information: Portions Copyright [yyyy] [name of copyright owner]
   *
   * CDDL HEADER END
   */
  /*
+  * Copyright 2014 Garrett D'Amore <garrett@damore.org>
+  *
   * Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  
  #ifndef _ICONV_H
  #define _ICONV_H
  
  #include <sys/feature_tests.h>
  #include <sys/types.h>
  
  #ifdef  __cplusplus
  extern "C" {
  #endif
  
  typedef struct _iconv_info *iconv_t;
  
  extern iconv_t  iconv_open(const char *, const char *);
  #ifdef _XPG6
  extern size_t   iconv(iconv_t, char **_RESTRICT_KYWD,
                  size_t *_RESTRICT_KYWD, char **_RESTRICT_KYWD,
                  size_t *_RESTRICT_KYWD);
*** 48,62 ****
  extern size_t   iconv(iconv_t, const char **_RESTRICT_KYWD,
                  size_t *_RESTRICT_KYWD, char **_RESTRICT_KYWD,
                  size_t *_RESTRICT_KYWD);
  #endif
  extern int      iconv_close(iconv_t);
- #else /* __STDC__ */
- extern iconv_t  iconv_open();
- extern size_t   iconv();
- extern int      iconv_close();
- #endif
  
  #ifdef  __cplusplus
  }
  #endif
  
--- 47,56 ----