Remove basic cleanup code

Remove basic cleanup code

This removes the basic cleanup code: make_cleanups, do_cleanups,
discard_cleanups, and friends.  This code is no longer needed, as
nothing in gdb makes an ordinary cleanup.  Final cleanups are still
needed.

2019-03-06  Tom Tromey  <tom@tromey.com>

	* top.c (quit_force): Update.
	* main.c (captured_command_loop): Update.
	* common/new-op.c (operator new): Update.
	* common/common-exceptions.c (struct catcher)
	<save_cleanup_chain>: Remove member.
	(exceptions_state_mc_init): Update.
	(exception_try_scope_entry): Return nullptr.
	(exception_try_scope_exit, exception_rethrow)
	(throw_exception_sjlj, throw_exception_cxx): Update.
	* common/cleanups.h (make_cleanup, make_cleanup_dtor)
	(all_cleanups, do_cleanups, discard_cleanups)
	(discard_final_cleanups, save_cleanups, save_final_cleanups)
	(restore_cleanups, restore_final_cleanups): Don't declare.
	(do_final_cleanups): Remove parameter.
	* common/cleanups.c (cleanup_chain, make_cleanup)
	(make_cleanup_dtor, all_cleanups, do_cleanups)
	(discard_my_cleanups, discard_cleanups)
	(discard_final_cleanups, save_my_cleanups, save_cleanups)
	(save_final_cleanups, restore_my_cleanups, restore_cleanups)
	(null_cleanup): Remove.
	(do_final_cleanups): Remove parameter.