Use function_view in a couple of places in breakpoint.c

Use function_view in a couple of places in breakpoint.c

This changes iterate_over_related_breakpoints and
map_breakpoint_numbers to take a function_view.  Then, it simplifies
the callers by using lambdas.  This then allows the removal of some
bookkeeping types.

gdb/ChangeLog
2017-09-20  Tom Tromey  <tom@tromey.com>

	* breakpoint.c (struct commands_info, do_map_commands_command):
	Remove.
	(commands_command_1): Update.
	(iterate_over_related_breakpoints): Take a function_view.
	(do_delete_breakpoint, do_map_delete_breakpoint): Remove.
	(delete_command): Update.
	(map_breakpoint_numbers): Take a function_view.
	(do_disable_breakpoint, do_map_delete_breakpoint): Remove.
	(disable_command): Update.
	(do_enable_breakpoint, do_map_enable_breakpoint): Remove.
	(enable_command): Update.
	(struct disp_data, do_enable_breakpoint_disp)
	(do_map_enable_once_breakpoint, do_map_enable_count_breakpoint)
	(do_map_enable_delete_breakpoint): Remove.
	(enable_once_command, enable_count_command, enable_delete_command)
	(delete_trace_variable_command): Update.