[AIX][test-suite] Use stat() on AIX to access d_type field (of dirent)

[amyk]

Summary

This patch makes use of stat() to access file type information, as the d_type
field of dirent.h is unavailable on AIX.

[amyk]

Ping.

[amyk]

Ping.

[amyk]

Gentle ping.
@hubert.reinterpretcast @ZarkoCA @stevewan @daltenty Did any of you have any comments regarding this change?

[amyk]

Gentle ping.

[stevewan]

LGTM. Thanks.

MultiSource/Applications/ClamAV/libclamav_readdb.c

#define CLI_DBEXT(ext)        \
   cli_strbcasestr(ext, ".inc")   || \
   cli_strbcasestr(ext, ".cvd")    \
     )
 
 static int dirent_compare(const struct dirent *a, const struct dirent *b) {
   int ret = strcmp(a->d_name, b->d_name);
   if (ret != 0)
     return ret;
+#ifdef _AIX
+       struct stat a_stat;
+       struct stat b_stat;
+       stat(a->d_name, &a_stat);
+       stat(b->d_name, &b_stat);
+       if (a_stat.st_mode < b_stat.st_mode) return -1;
+       if (a_stat.st_mode > b_stat.st_mode) return 1;
+#else
   if (a->d_type < b->d_type) return -1;
   if (a->d_type > b->d_type) return 1;
+#endif
   if (a->d_reclen < b->d_reclen) return -1;
   if (a->d_reclen > b->d_reclen) return 1;
   return 0;
 }
 
 static int cli_loaddbdir_l(const char *dirname, struct cl_engine **engine, unsigned int *signo, unsigned int options)
 {
   DIR *dd;