* DevNotes: Add entry cgf-000013.

* DevNotes: Add entry cgf-000013.
* cygserver_ipc.h (ipc_set_proc_info): Use _cygtls::ipc_set_proc_info to set
per-thread signal arrived value.
* cygthread.cc (cygthread::detach): Use per-thread signal_arrived via
set_thread_waiting.
* fork.cc (_cygtls::fixup_after_fork): Clear signal_arrived.
(_cygtls::remove): Close any signal_arrived handle when thread exists.
(_cygtls::find_tls): Remove unneeded function.
* cygtls.h: Update copyright.
(class _cygtls): Reorganize to help avoid rebuilding newlib when structure
changes.
(_cygtls::event): Delete.
(_cygtls::threadkill): Ditto.
(_cygtls::signal_waiting): Declare new bool.
(_cygtls::find_tls): Delete declaration.
(_cygtls::set_threadkill): Ditto.
(_cygtls::reset_threadkill): Ditto.
(_cygtls::set_signal_arrived): Declare new function.
(class set_thread_waiting): Declare new class.
* cygwait.cc (cw_nowait_storage): Define.
(cygwait): Set per-thread signal_arrived via set_thread_waiting.  Don't
special-case _main_tls.
* cygwait.h (cw_nowait): Define.
(cw_infinite): Ditto.
(cygwait): Redefine pathological wait-only case.
* dcrt0.cc (dll_crt0_0): Remove call to now-defunct events_init().
(dll_crt0_1): Remove call to now-defunct create_signal_arrived().
* exceptions.cc: Reflect set_signal_mask() argument reordering throughout.
Remove signal mask synchronization throughout.
(events_init): Delete definition.
(mask_sync): Delete now-unneeded mask synchronization.
(set_signal_mask): Reverse order of arguments to "standard" to, from layout.
Rename "newmask" argument to "setmask".  Remove debugging.
(sig_handle_tty_stop): Use cancelable_wait rather than WFMO.
(_cygtls::interrupt_setup): Don't treat "threadkill" events specially.
Conditionally set signal_arrived depending on whether the thread has created it
or not.
(sigpacket::process): Reorganize to reflect thread-specific sending of signals
which is more in line with the way it was actually supposed to work.
* fhandler_socket.cc (get_inet_addr): Use cancelable_wait rather than
IsEventSignalled to avoid potential race.
(fhandler_socket::wait_for_events): Set signal_arrived event using
set_thread_waiting().
(fhandler_socket::close): Use cygwait for the case of just waiting 10 ms for a
signal.
* fhandler_tape.cc (fhandler_dev_tape::_lock): Use cancelable_wait rather than
WFMO.  Redo switch/case tests accordingly.
* fhandler_termios.cc (fhandler_termios::bg_check): Use cygwait for case of
just waiting 0 ms for a potential signal.
* fhandler_tty.cc (fhandler_pty_master::process_slave_output): Use
cancelable_wait rather than WFSO.
* fhandler_windows.cc (fhandler_windows::read): Set per-thread signal_arrived
via set_thread_waiting().
* flock.cc (lf_setlock): Ditto.
* select.cc (pselect): Ditto.  Set per-thread signal_arrived using
set_thread_waiting().
* gendef: Don't special case handling of _cygtls::sig for threads.
* gentls_offsets: Use #pragma once in tlsoffsets.h.
* ntdll.h: Use #pragma once.
* poll.cc: Reflect set_signal_mask() argument reordering.
* posix_ipc.cc (ipc_mutex_lock): Use cancelable_wait rather than WFMO.
(ipc_cond_timedwait): Set perl-thread signal arrived using
set_thread_waiting().
* security.h: Use #pragma once.
* signal.cc (abort): Reflect set_signal_mask() argument reordering.
(clock_nanosleep): Ditto.  Change call to cancelable_wait to properly specify
handling of cancel and interrupt.
(sigwaitinfo): Remove handling of per-thread event in favor of per-thread
signal_arrived.  Use cancelable_wait rather than WFSO.
* sigproc.cc (signal_arrived): Delete definition.
(create_signal_arrived): Ditto.
* sigproc.h (signal_arrived): Delete declaration.
(set_signal_mask): Avoid defining as a "C" function.  Don't conditionally
declare.
(create_signal_arrived): Delete declaration.
* syscalls.cc (rename): Use cygwait() rather than WFSO.
* thread.h (fast_mutex::lock): Use cw_infinite rather than LARGE_NULL.
* wait.cc (wait4): Ditto.
* thread.cc (pthread_mutex::lock): Ditto.
(pthread::join): Ditto.
(semaphore::_wait): Ditto.
(pthread_kill): Remove set_threadkill() accommodation.
* tlsoffsets.h: Regenerate.