* configure.ac: Check whether struct dirent has a d_type field

* src/dir.c (dir_contents_file_exists_p): Use the autoconf macro
HAVE_STRUCT_DIRENT_D_TYPE rather than relying on the GNU libc-
specific _DIRENT_HAVE_D_TYPE.
* lib/glob.c: Set HAVE_D_TYPE if HAVE_STRUCT_DIRENT_D_TYPE.
3 files changed