cygwin 3.6.5-1

[Jon Turney]

The following packages have been uploaded to the Cygwin distribution:

* cygwin-3.6.5-1
* cygwin-devel-3.6.5-1
* cygwin-doc-3.6.5-1

Fixes:
------

- Fix two minor bugs in clock and POSIX timer handling.

- Fix an ordering problem in sys/termios.h.
   Addresses: https://cygwin.com/pipermail/cygwin/2025-July/258474.html

- Fix doxygen hang due to a deadlock between fclose() and fork().
   Addresses: https://cygwin.com/pipermail/cygwin-apps/2025-May/044318.html
   Addresses: https://cygwin.com/pipermail/cygwin/2025-June/258323.html

- Fix multi-thread safety of system().
   Addresses: https://cygwin.com/pipermail/cygwin/2025-June/258324.html

- Revert fix handling of invalid 4 byte UTF-8 sequence. It was broken.
   Addresses: https://cygwin.com/pipermail/cygwin/2025-July/258513.html

- Instead, fix internal conversion of filenames in case of an invalid
   4 byte UTF-8 sequence.
   Addresses: https://cygwin.com/pipermail/cygwin/2025-June/258358.html

- Make process_fd correctly handle pty and console.
   Addresses: https://cygwin.com/pipermail/cygwin/2025-May/258167.html

- Fix Ctrl-O (FLUSHO) handling.
   Addresses: https://cygwin.com/pipermail/cygwin/2025-August/258717.html

- Fix multi-thread safety of fork()/exec() by adding the same locking as
   was done for spawn.
   Addresses: https://cygwin.com/pipermail/cygwin/2025-September/258801.html

- Fix native symlink to '.' (a regression in 3.6.4)