Change tui_update_breakpoint_info to be a method
    
    This changes tui_update_breakpoint_info to be a method on
    tui_source_window_base.
    
    gdb/ChangeLog
    2019-08-16  Tom Tromey  <tom@tromey.com>
    
    	* tui/tui-winsource.h (struct tui_source_window_base)
    	<update_breakpoint_info>: Declare.
    	(tui_update_breakpoint_info): Don't declare.
    	* tui/tui-winsource.c (tui_source_window_base::update_source_window_as_is)
    	(tui_update_all_breakpoint_info): Update.
    	(tui_source_window_base::update_breakpoint_info): Rename from
    	tui_update_breakpoint_info.
    	(tui_source_window_base::update_exec_info): Update.