Perform whitespace cleanup throughout.

* dcrt0.cc (signal_shift_subtract): Eliminate ancient backwards compatibility.
(check_sanity_and_sync): Ditto.
* winsup.h (SIGTOMASK): Ditto.  Just use constant in signal calculation.
* include/cygwin/version: Remove backwards signal mask compatibility define.
* path.cc (symlink_info::check_sysfile): Cosmetic change.
* registry.cc (get_registry_hive_path): Remove unneeded variable.
* exceptions.cc (handle_sigsuspend): Eliminate thread signal mask and use
either main sigmask or current thread sigmask.
(set_process_mask): Ditto.
(sighold): Ditto.
(sigrelse): Ditto.
(sigset): Ditto.
(set_process_mask_delta): Ditto.
(_cygtls::call_signal_handler): Ditto.
* fhandler_process.cc (format_process_status): Ditto.
* fhandler_termios.cc (fhandler_termios::bg_check): Ditto.
* pinfo.h (class pinfo): Ditto.
* select.cc (pselect): Ditto.
* signal.cc (sigprocmask): Ditto.
(abort): Ditto.
(sigpause): Ditto.
(sigsend): Ditto.
(wait_sig): Ditto.
* thread.h (pthread::parent_tls): New member.
* thread.cc (pthread::pthread): Record parent_tls here.
(pthread::thread_init_wrapper): Initialize sigmask from parent thread.

winsup/cygwin/thread.cc

@@ -376,6 +376,7 @@ pthread::pthread ():verifyable_object (PTHREAD_MAGIC), win32_obj_id (0),
 {
   if (this != pthread_null::get_null_pthread ())
     threads.insert (this);
+  parent_tls = &_my_tls;
 }
 
 pthread::~pthread ()
@@ -1738,6 +1739,7 @@ pthread::thread_init_wrapper (void *arg)
   // if thread is detached force cleanup on exit
   if (thread->attr.joinable == PTHREAD_CREATE_DETACHED && thread->joiner == NULL)
     thread->joiner = thread;
+  _my_tls.sigmask = thread->parent_tls->sigmask;
   thread->mutex.unlock ();
 
   thread_printf ("started thread %p %p %p %p %p %p", arg, &_my_tls.local_clib,