The first patch in this series went through several iterations as I'd
forgotten how many places had to be touched to add a new event and a
new event type.

This patch simplifies the process using two new ".def" files.  Now, a
new event type can be added by adding a line to "py-event-types.def",
and a new event registry can be added by adding a line to
"py-all-events.def".

ChangeLog
2017-09-11  Tom Tromey  <tom@tromey.com>

	* python/python.c (do_start_initialization): Use
	py-event-types.def to initialize types.
	Define all object type structures.
	* python/python-internal.h: Don't declare event initialization
	functions.
	* python/py-threadevent.c (thread_event_object_type): Don't
	define.
	* python/py-stopevent.c (stop_event_object_type): Don't define.
	* python/py-signalevent.c (signal_event_object_type): Don't
	declare or define.
	* python/py-newobjfileevent.c (new_objfile_event_object_type)
	(clear_objfiles_event_object_type): Don't declare or define.
	* python/py-infevents.c (inferior_call_pre_event_object_type)
	(inferior_call_post_event_object_type)
	(register_changed_event_object_type)
	(memory_changed_event_object_type): Don't declare or define.
	* python/py-inferior.c (new_thread_event_object_type)
	(new_inferior_event_object_type)
	(inferior_deleted_event_object_type): Don't declare or define.
	* python/py-exitedevent.c (exited_event_object_type): Don't
	declare or define.
	* python/py-evts.c (gdbpy_initialize_py_events): Use
	py-all-events.def.
	* python/py-events.h (thread_event_object_type): Don't declare.
	(events_object): Use py-all-events.def.
	* python/py-event.h (GDBPY_NEW_EVENT_TYPE): Remove.  Use
	py-event-types.def.
	* python/py-event-types.def: New file.
	* python/py-continueevent.c (create_continue_event_object): Don't
	declare or define.
	* python/py-bpevent.c (breakpoint_event_object_type): Don't
	declare or define.
	* python/py-all-events.def: New file.