* cygtls.h (waitq): Declare structure here.

* cygtls.h (waitq): Declare structure here.
(_cygtls::wq): Declare.
* cygtls.cc (_cygtls::fixup_after_fork): Clear wq.thread_ev to avoid using an
invalid event handle in forked process.
* dcrt0.cc (waitq_storage): Delete.
(threadstuff): Remove waitq_storage.
* perthread.h (per_thread_waitq): Delete.
(waitq_storage): Delete declaration.
* sigproc.cc (sigproc_init): Remove perthread waitq consideration.
* sigproc.h (waitq): Delete declaration.
* wait.cc (wait4): Use _my_tls waitq structure rather than per_thread.
* cygtls.h (_cygtls::newmask): Delete member.
(_cygtls::deltamask): New member.
* gendef (_sigdelayed): Replace the call to set_process_mask by a call to
set_process_mask_delta.
* exceptions.cc (handle_sigsuspend): Do not filter tempmask.  Or
SIG_NONMASKABLE in deltamask as a flag.
(_cygtls::interrupt_setup): Set deltamask only.
(set_process_mask_delta): New function.
(_cygtls::call_signal_handler): Replace the first call to set_process_mask by a
call to set_process_mask_delta.
* tlsoffsets.h: Regenerate.