bug#53260: char-syntax differs in interpreter and bytecode

[Eli Zaretskii]

> From: Mattias Engdegård <mattiase@acm.org>
> Date: Sat, 15 Jan 2022 18:29:41 +0100
> Cc: Lars Ingebrigtsen <larsi@gnus.org>, 53260@debbugs.gnu.org
> 
> 2. Remove make_char_multibyte(c) from Bchar_syntax because it seems to be the 
> wrong thing to do: in a unibyte buffer, wouldn't the syntax table be indexed 
> by byte value (so that char 255 in the buffer corresponds to entry 255 in the 
> syntax table rather than entry 0x3fffff)?

I don't think we want to support unibyte buffers which have some text
that is syntactically significant.  A unibyte buffer is just a stream
of raw bytes, they are not characters.