fix compilation errors due to 'restrict'

[Bruno Haible]

Some modules were using 'restrict' in a declaration in string.h without
ensuring it's properly defined.

2007-05-13  Bruno Haible  <address@hidden>

        * stpcpy.m4 (gl_FUNC_STPCPY): Require AC_C_RESTRICT.
        * stpncpy.m4 (gl_FUNC_STPNCPY): Likewise.
        * strsep.m4 (gl_FUNC_STRSEP): Likewise.
        * strtok_r.m4 (gl_FUNC_STRTOK_R): Likewise.
        (gl_PREREQ_STRTOK_R): Don't require it here.

*** m4/stpcpy.m4        27 Jan 2007 14:43:17 -0000      1.4
--- m4/stpcpy.m4        13 May 2007 21:53:41 -0000
***************
*** 1,4 ****
! # stpcpy.m4 serial 3
  dnl Copyright (C) 2002, 2007 Free Software Foundation, Inc.
  dnl This file is free software; the Free Software Foundation
  dnl gives unlimited permission to copy and/or distribute it,
--- 1,4 ----
! # stpcpy.m4 serial 4
  dnl Copyright (C) 2002, 2007 Free Software Foundation, Inc.
  dnl This file is free software; the Free Software Foundation
  dnl gives unlimited permission to copy and/or distribute it,
***************
*** 9,14 ****
--- 9,17 ----
    dnl Persuade glibc <string.h> to declare stpcpy().
    AC_REQUIRE([AC_GNU_SOURCE])
  
+   dnl The stpcpy() declaration in lib/string_.h uses 'restrict'.
+   AC_REQUIRE([AC_C_RESTRICT])
+ 
    AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
    AC_REPLACE_FUNCS(stpcpy)
    if test $ac_cv_func_stpcpy = no; then
*** m4/stpncpy.m4       27 Jan 2007 14:43:17 -0000      1.9
--- m4/stpncpy.m4       13 May 2007 21:53:41 -0000
***************
*** 1,4 ****
! # stpncpy.m4 serial 6
  dnl Copyright (C) 2002-2003, 2005-2007 Free Software Foundation, Inc.
  dnl This file is free software; the Free Software Foundation
  dnl gives unlimited permission to copy and/or distribute it,
--- 1,4 ----
! # stpncpy.m4 serial 7
  dnl Copyright (C) 2002-2003, 2005-2007 Free Software Foundation, Inc.
  dnl This file is free software; the Free Software Foundation
  dnl gives unlimited permission to copy and/or distribute it,
***************
*** 9,14 ****
--- 9,17 ----
    dnl Persuade glibc <string.h> to declare stpncpy().
    AC_REQUIRE([AC_GNU_SOURCE])
  
+   dnl The stpncpy() declaration in lib/string_.h uses 'restrict'.
+   AC_REQUIRE([AC_C_RESTRICT])
+ 
    AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
  
    dnl Both glibc and AIX (4.3.3, 5.1) have an stpncpy() function
*** m4/strsep.m4        27 Jan 2007 14:43:17 -0000      1.5
--- m4/strsep.m4        13 May 2007 21:53:41 -0000
***************
*** 1,4 ****
! # strsep.m4 serial 5
  dnl Copyright (C) 2002, 2003, 2004, 2007 Free Software Foundation, Inc.
  dnl This file is free software; the Free Software Foundation
  dnl gives unlimited permission to copy and/or distribute it,
--- 1,4 ----
! # strsep.m4 serial 6
  dnl Copyright (C) 2002, 2003, 2004, 2007 Free Software Foundation, Inc.
  dnl This file is free software; the Free Software Foundation
  dnl gives unlimited permission to copy and/or distribute it,
***************
*** 9,14 ****
--- 9,17 ----
    dnl Persuade glibc <string.h> to declare strsep().
    AC_REQUIRE([AC_GNU_SOURCE])
  
+   dnl The strsep() declaration in lib/string_.h uses 'restrict'.
+   AC_REQUIRE([AC_C_RESTRICT])
+ 
    AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
    AC_REPLACE_FUNCS(strsep)
    if test $ac_cv_func_strsep = no; then
*** m4/strtok_r.m4      27 Jan 2007 14:43:17 -0000      1.5
--- m4/strtok_r.m4      13 May 2007 21:53:41 -0000
***************
*** 1,4 ****
! # strtok_r.m4 serial 5
  dnl Copyright (C) 2002, 2003, 2004, 2007 Free Software Foundation, Inc.
  dnl This file is free software; the Free Software Foundation
  dnl gives unlimited permission to copy and/or distribute it,
--- 1,4 ----
! # strtok_r.m4 serial 6
  dnl Copyright (C) 2002, 2003, 2004, 2007 Free Software Foundation, Inc.
  dnl This file is free software; the Free Software Foundation
  dnl gives unlimited permission to copy and/or distribute it,
***************
*** 6,11 ****
--- 6,14 ----
  
  AC_DEFUN([gl_FUNC_STRTOK_R],
  [
+   dnl The strtok_r() declaration in lib/string_.h uses 'restrict'.
+   AC_REQUIRE([AC_C_RESTRICT])
+ 
    AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
    AC_REPLACE_FUNCS(strtok_r)
    AC_CHECK_DECLS_ONCE(strtok_r)
***************
*** 17,21 ****
  
  # Prerequisites of lib/strtok_r.c.
  AC_DEFUN([gl_PREREQ_STRTOK_R], [
!   AC_REQUIRE([AC_C_RESTRICT])
  ])
--- 20,24 ----
  
  # Prerequisites of lib/strtok_r.c.
  AC_DEFUN([gl_PREREQ_STRTOK_R], [
!   :
  ])