Ticket #3930: clarify name of struct stat members for Apple compilation.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>

lib/global.h

@@ -137,6 +137,13 @@
 #define OS_SORT_CASE_SENSITIVE_DEFAULT TRUE
 #define UTF8_CHAR_LEN 6
 
+/* struct stat members */
+#ifdef __APPLE__
+#define st_atim st_atimespec
+#define st_ctim st_ctimespec
+#define st_mtim st_mtimespec
+#endif
+
 /* Used to distinguish between a normal MC termination and */
 /* one caused by typing 'exit' or 'logout' in the subshell */
 #define SUBSHELL_EXIT 128