(previous_async_command): Remove.
(mi_cmd_gdb_exit): Adjust.
(mi_cmd_exec_interrupt): Don't dance with previous_async_command.
(mi_cmd_target_select): Adjust.
(mi_cmd_execute): Don't set previous_async_command. Free token
here even in async mode.
(mi_execute_async_cli_command): Adjust.
(mi_exec_async_cli_cmd_continuation): Adjust. Do not free the
token.
(mi_load_progress): Adjust.
721c02def4