bug#12915: 24.2.50; Visiting a file via drag-and-drop should add it to the historyof visited files

[Drew Adams]

>  > Maybe a more automatic way is to provide a 
>  > `display-buffer-hook'...
> 
> `buffer-list-update-hook' ?

File-name input is not about a change in the list of buffers or the displayed
files.  It is about files that the user has interactively requested to access.
In particular, requested by entering the file name.