bug#24749: Making sure syntax-propertize is called

[Dmitry Gutov]

On 21.10.2016 00:14, Stefan Monnier wrote:

> Nowadays, syntax-propertize is automatically called ondemand by the sexp
> functions, but only if parse-sexp-lookup-properties is non-nil.
> See bug#4920 for an example of the problem and the fix we installed.
>
> I suggest we install the patch below instead, so as to fix this bug in
> more/all major modes at once.

Good suggestion. Although can't we just set the default value to t, and 
simply not use it when syntax-propertize-function is not set?