Remove some cleanups from breakpoint.c

Remove some cleanups from breakpoint.c

This removes some cleanups from breakpoint.c, replacing them with C++
data structures.

2017-10-11  Tom Tromey  <tom@tromey.com>

	* breakpoint.c (commands_command_1): Use std::string.
	(cleanup_executing_breakpoints): Remove.
	(bpstat_do_actions_1): Use scoped_restore.
	(bpstat_check_watchpoint): Use std::string.
	(decode_static_tracepoint_spec): Likewise.
	(break_range_command): Likewise.
	(watch_command_1): Likewise.
	(compare_breakpoints): Change argument types.
	(clear_command): Use std::vector.
	(cleanup_executing_breakpoints): Remove.
	(update_global_location_list): Use unique_xmalloc_ptr.
	(strace_command): Remove unused declaration.