Merge syntax-propertize--done and parse-sexp-propertize-done

Merge syntax-propertize--done and parse-sexp-propertize-done

* lisp/emacs-lisp/syntax.el (syntax-propertize--done): Remove.
(syntax-propertize): Set syntax-propertize--done even if
syntax-propertize-function is nil.  Avoid recursive invocations.
(syntax-propertize-chunks): New var.
(internal--syntax-propertize): Use it.  Rename from syntax--jit-propertize.
Simplify.
(parse-sexp-propertize-function): Don't set any more.

* src/syntax.c (SETUP_SYNTAX_TABLE): Call parse_sexp_propertize as needed.
(parse_sexp_propertize): Don't assume charpos is not yet propertized.
Call Qinternal__syntax_propertize instead of
Vparse_sexp_propertize_function.  Truncate e_property if needed.
(update_syntax_table_forward): Streamline.
(syms_of_syntax): Define Qinternal__syntax_propertize.
(syntax_propertize__done): Rename from parse_sexp_propertize_done.