Change tui_check_register_values to be a method
This changes tui_check_register_values to be a method on
tui_data_window. An additional check in tui_register_changed is
needed, because TUI_DATA_WIN could be NULL at this point.
2019-08-20 Tom Tromey <tom@tromey.com>
* tui/tui-regs.h (struct tui_data_window) <check_register_values>:
Declare.
(tui_check_register_values): Don't declare.
* tui/tui-regs.c (tui_data_window::check_register_values): Rename
from tui_check_register_values.
* tui/tui-hooks.c (tui_register_changed): Update.