[m-rev.] for post-commit review: simplify representation of builtin ops

[Julien Fischer]

On Sat, 13 Apr 2024, Zoltan Somogyi wrote:

> Simplify the representation of builtin ops.
> 
> compiler/builtin_ops.m:
>     Replace the approach we use to represent builtin operations.
>     Instead of a general type restricted by purpose-specific insts,
>     use specific types.
> 
> compiler/call_gen.m:
> compiler/ml_call_gen.m:
>     Conform to the change above.
> 
> compiler/bytecode_gen.m:
>     Partially conform to the change above. Leave some parts NYI.

That's fine.

Julien.