* select.h (select_stuff): Remove variable names from parameter declarations.

* select.h (select_stuff): Remove variable names from parameter declarations.
(select_info): Ditto.
(select_record::dump_select_record): Declare new debugging-only function.
(select_info): Zero all fields.
(select_pipe_info): Ditto.
(select_socket_info): Ditto.
(select_serial_info): Ditto.
(select_mailslot_info): Ditto.
* select.cc (select_record::dump_select_record): Define new debugging-only
function.
(select_stuff::test_and_set): Call dump_select_record when debugging.
* thread.cc (pthread_mutex::unlock): Revert setting of tid to NULL since, in
this context, it is a number, not a pointer.
(pthread_spinlock::unlock): Ditto.