idevicebackup2: Fix scan_directory() for platforms not having d_type in struct dirent

configure.ac

diff --git a/configure.ac b/configure.ac
index ec210fc..69ff13b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -83,6 +83,8 @@
 esac
 AM_CONDITIONAL(WIN32, test x$win32 = xtrue)
 
+AC_CHECK_MEMBER(struct dirent.d_type, AC_DEFINE(HAVE_DIRENT_D_TYPE, 1, [define if struct dirent has member d_type]),, [#include <dirent.h>])
+
 # Cython Python Bindings
 AC_ARG_WITH([cython],
             [AS_HELP_STRING([--without-cython],

tools/idevicebackup2.c

diff --git a/tools/idevicebackup2.c b/tools/idevicebackup2.c
index 02611a1..f7ea53a 100644
--- a/tools/idevicebackup2.c
+++ b/tools/idevicebackup2.c
@@ -254,7 +254,13 @@
 			}
 			char *fpath = string_build_path(path, ep->d_name, NULL);
 			if (fpath) {
+#ifdef HAVE_DIRENT_D_TYPE
 				if (ep->d_type & DT_DIR) {
+#else
+				struct stat st;
+				if (stat(fpath, &st) != 0) return;
+				if (S_ISDIR(st.st_mode)) {
+#endif
 					struct entry *ent = malloc(sizeof(struct entry));
 					if (!ent) return;
 					ent->name = fpath;