xreadlink can assume unistd

[Bruno Haible]

The 'relocatable' module now assumes the 'unistd' module (as well as
'stdbool' and others), therefore xreadlink.c can assume it as well.
And the module description should be clear about this requirement.

2007-03-03  Bruno Haible  <address@hidden>

        * lib/xreadlink.c: Include <unistd.h> unconditionally.
        * modules/xreadlink (Depends-on): Add unistd.
        * modules/xreadlink-with-size (Depends-on): Likewise.

*** lib/xreadlink.c     1 Mar 2007 00:07:34 -0000       1.25
--- lib/xreadlink.c     3 Mar 2007 19:15:44 -0000
***************
*** 31,39 ****
  #include <limits.h>
  #include <sys/types.h>
  #include <stdlib.h>
! #if HAVE_UNISTD_H
! # include <unistd.h>
! #endif
  
  #ifndef SIZE_MAX
  # define SIZE_MAX ((size_t) -1)
--- 31,37 ----
  #include <limits.h>
  #include <sys/types.h>
  #include <stdlib.h>
! #include <unistd.h>
  
  #ifndef SIZE_MAX
  # define SIZE_MAX ((size_t) -1)
*** modules/xreadlink   1 Mar 2007 07:34:20 -0000       1.14
--- modules/xreadlink   3 Mar 2007 19:15:44 -0000
***************
*** 8,13 ****
--- 8,14 ----
  Depends-on:
  readlink
  ssize_t
+ unistd
  xalloc
  
  configure.ac:
*** modules/xreadlink-with-size 1 Mar 2007 07:34:20 -0000       1.3
--- modules/xreadlink-with-size 3 Mar 2007 19:15:44 -0000
***************
*** 8,13 ****
--- 8,14 ----
  Depends-on:
  readlink
  ssize_t
+ unistd
  xalloc
  
  configure.ac: