Reserve less file space if possible in a directory entry

On POSIX systems, we can use the maximum file length instead of maximum
path length. This saves space and time for clearing the memory.

Author: nielsdos

main/php_streams.h

@@ -107,7 +107,11 @@ typedef struct _php_stream_statbuf {
 } php_stream_statbuf;
 
 typedef struct _php_stream_dirent {
+#ifdef NAME_MAX
+	char d_name[NAME_MAX + 1];
+#else
 	char d_name[MAXPATHLEN];
+#endif
 } php_stream_dirent;
 
 /* operations on streams that are file-handles */