Ignore quit while getting interprogram paste in kill-new

Ignore quit while getting interprogram paste in kill-new

On X, if the current selection owner is not responding to selection
requests, the user may want to take ownership of the selection.  The
obvious way to do this is to kill some text (which a user might also
be doing just as part of normal editing at the time the selection
owner becomes nonresponsive).  However, if
save-interprogram-paste-before-kill is non-nil, then killing text will
hang until the user quits, and this quit will abort the entire
kill-new, preventing the user from taking ownership of the selection.

Now instead if the user quits while we are attempting to retrieve the
selection from hanging owner, we will proceed to take ownership of the
selection as normal, resolving the problem.

(One example of a selction owner that might not be responding to
selection requests is another instance of Emacs itself; while Emacs is
blocked in call-process or Lisp execution, it currently does not
respond to selection requests.)

* lisp/simple.el (kill-new): Ignore quit while getting interprogram
paste (bug#64423)