* lisp/font-lock.el (font-lock-beginning-of-syntax-function): Remove
(font-lock-fontify-block): Don't let-bind it.
(font-lock-compile-keywords): Don't use it.
(font-lock-set-defaults): Don't set it. Allow the variable alist to
start one slot earlier, instead.
* lisp/emacs-lisp/syntax.el (font-lock-beginning-of-syntax-function):
Don't declare.
(syntax-ppss): Don't use it either.
* lisp/font-core.el (font-lock-defaults): Remove SYNTAX-BEGIN
from docstring.
* doc/emacs/display.texi (Font Lock): Don't mention
font-lock-beginning-of-syntax-function.
* doc/lispref/modes.texi (Font Lock Basics): Update description of
font-lock-defaults.
(Syntactic Font Lock): Remove font-lock-beginning-of-syntax-function.
* lisp/loadhist.el (unload-feature-special-hooks):
Remove font-lock-beginning-of-syntax-function.
* lisp/obsolete/lazy-lock.el (lazy-lock-fontify-region):
* lisp/emacs-lisp/lisp.el (beginning-of-defun-raw): Don't let-bind
font-lock-beginning-of-syntax-function.