feat(tazjin/emacs): implement reliably-switch-buffer r/6520

Adds a completing-read function (defaulting to ivy for me, but it
doesn't matter) that offers a reliable alternative to standard
buffer-switching implementations.

In particular, this implementation retains a mapping of
buffer names to their buffer *objects*, so that the correct buffer is
selected even if some renaming took place during the selection.

I tried to account for a bunch of the common behaviours I could think
of:

* invisible buffers are ... invisible
* entering a buffer name manually creates that buffer, if there is no
  match
* ... unless that buffer is an invisible buffer, in which case it is
  selected and switched to
* the first element is always `(other-buffer (current-buffer))`,
  because of the ordering of #'buffer-list

Yet, the entire code of my implementation is less than the *setup*
code of ivy-switch-buffers, so it's possible I missed something. Well,
I'll find out ...

Change-Id: I08be0da0863d06c9a930e5efaf916719655db90e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9147
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI

0 files changed, 0 insertions, 0 deletions