[m-rev.] for review: delete references to Erlang in the compiler

[Julien Fischer]

On Wed, 28 Oct 2020, Zoltan Somogyi wrote:

>
> 2020-10-28 13:47 GMT+11:00 "Julien Fischer" <jfischer at opturion.com>:
>> Because I want to install a library in every grade that a Mercury
>> installation has installed except for Erlang, typically because the
>> Erlang backend is generating invalid code or doing soemthing else which
>> would otherwise break the installation process.   My mercury-json
>> library is setup to do exactly that for exactly that reason.
>
> OK, thanks for that. But do you want to keep that option around
> after the erlang backend is deleted? If not, then an expanded
> error message would seem sufficient.

At the moment mercury-json maintains compatibilty with Mercury 20.06 and
it's certainly possible for 20.06 installations have the erlang grade
installed.

It's not a huge problem for me personally as I can just create a branch
for the 20.06 compatible version of mercury-json and remove the exclusion
of the erlang grade from the trunk; I only raise because you do risk
breaking install targets for libraries that maintain compatibility with
older versions of Mercury.

Julien.