canonicalize-lgpl: fix compilation error on mingw

[Bruno Haible]

This fixes a build error on mingw, if you happen to use the sys_stat module
together with the canonicalize-lgpl module.


2006-12-23  Bruno Haible  <[EMAIL PROTECTED]>

        * lib/canonicalize-lgpl.c (__realpath): Test HAVE_READLINK instead of
        S_ISLNK.
        Needed because gnulib's sys/stat.h replacement defines S_ISLNK on
        mingw.

*** gnulib-20061208/lib/canonicalize-lgpl.c.bak 2006-11-06 19:21:35.000000000 
+0100
--- gnulib-20061208/lib/canonicalize-lgpl.c     2006-12-23 04:55:49.000000000 
+0100
***************
*** 101,107 ****
    char *rpath, *dest, *extra_buf = NULL;
    const char *start, *end, *rpath_limit;
    long int path_max;
! #ifdef S_ISLNK
    int num_links = 0;
  #endif
  
--- 101,107 ----
    char *rpath, *dest, *extra_buf = NULL;
    const char *start, *end, *rpath_limit;
    long int path_max;
! #if HAVE_READLINK
    int num_links = 0;
  #endif
  
***************
*** 231,237 ****
  #endif
            goto error;
  
! #ifdef S_ISLNK
          if (S_ISLNK (st.st_mode))
            {
              char *buf;
--- 231,237 ----
  #endif
            goto error;
  
! #if HAVE_READLINK
          if (S_ISLNK (st.st_mode))
            {
              char *buf;