bug#19064: 25.0.50; `message' overwrites `y-or-n-p' prompt, so user misses it

[Drew Adams]

> It would be helpful to have a recipe.

Sorry, but recent Emacs 25 snapshots I have just crash all
the time.  I cannot use Emacs 25 for much of anything, I'm
afraid.

But I think the bug description here should be sufficient.
In particular, does this not seem appropriate to consider?

  Seems like whenever `y-or-n-p' (or just `read-key') is waiting
  for a key, `message' should do nothing.  Either it should echo
  its message after the key is read or (maybe better) it should
  do nothing at all.  As it stands now, this seems like a basic
  UI problem, not just a minor annoyance.