Merge from origin/emacs-25

6620944 (cl-union): Do not ignore :test argument when lists are equal.
17dd3fb Add `isearch' to `basic-faces'
c1ec743 Make $, : and @ "prefix characters" in ruby-mode
e72a26e Make find-tag-default-bounds more strict
1bc0e0a Minor fixes in filenotify.el

diff --cc doc/lispref/display.texi
Simple merge

diff --cc lisp/progmodes/ruby-mode.el
Simple merge

diff --cc lisp/replace.el
Simple merge

diff --cc lisp/subr.el
Simple merge