[m-rev.] for review: don't compute has_main/no_main

[Julien Fischer]

On Sat, 7 Nov 2020, Zoltan Somogyi wrote:

> For review by anyone.

> Don't compute has_main/no_main.
> 
> That info hasn't been used in a long time (since we deleted the IL backend,
> according to an old comment).

That's fine.

Julien.