[m-rev.] for review: avoid instances containing cluases in the io module

[Julien Fischer]

On Sun, 11 Feb 2024, Julien Fischer wrote:
>
> Avoid instances containing clauses in the io module.
>
> The current implementation of intermodule optimization does not allow 
> typeclass
> instance definitions containing clauses to occur in .opt files. In 
> particular,
> this affects a number of the stream class instances in the io module. This 
> diff
> switches over to use 'pred(...) is predname' style of method definition
> throughout the io module.
>
> library/io.m:
>     Avoid instances that contains clauses; introduce additional private
>     predicates where necessary to make this possible.


In the absence of any review comments, I will commit this one later this
evening.

Julien.