bug#9148: Make `comment-normalize-vars' more syntax-aware

[Stefan Monnier <monnier@iro.umontreal.ca>]

> The point is that you can define a major mode with different syntax
> tables in different parts of the text (using the syntax-table text
> property), but instead of using that information to determine
> comment-start and the other variables, `comment-normalize-vars' still
> relies on `comment-start' being hard-coded (which doesn't really make
> sense in a buffer with multiple comment syntaxes), even when
> `comment-use-syntax' is set and the syntax-table information is
> sufficient.

But this is part of a much larger problem (multiple major modes in the
same buffer).

Basically you're suggesting to use the syntax-table property as a way to
specify the major mode used in each part and then teach newcomment.el to
never use buffer-local variables but only the syntax-table around point.

It might be a good idea, but it's a non-trivial change (and still
leaves open the question of how to specify that I want //...\n for the
C chunks and (*...*) for the Pascal chunks).


        Stefan