gdb/

gdb/
	* ia64-linux-nat.c (ia64_linux_status_is_event): New function.
	(_initialize_ia64_linux_nat): Install it.
	* linux-nat.c (sigtrap_is_event, linux_nat_status_is_event)
	(linux_nat_set_status_is_event): New.
	(stop_wait_callback, count_events_callback, select_event_lwp_callback)
	cancel_breakpoints_callback, linux_nat_filter_event)
	(linux_nat_wait_1): Use linux_nat_status_is_event.
	* linux-nat.h (linux_nat_set_status_is_event): New prototype.

gdb/testsuite/
	* gdb.threads/ia64-sigill.exp: New file.
	* gdb.threads/ia64-sigill.c: New file.