(stdio_file_write_async_safe): New function.
(struct stdio_file): New member fd.
(stdio_file_new): Initialize to_write_async_safe, fd.
- (stdio_file_read, stdio_file_isatty): New stdio->fd instead of calling fileno.
+ (stdio_file_read, stdio_file_isatty): New stdio->fd instead of calling
+ fileno.
* ui-file.h (ui_file_write_async_safe_ftype): New typedef.
(set_ui_file_write_async_safe): Declare.
(ui_file_write_async_safe): Declare.