[m-rev.] for post-commit review: carve var_db.m out of var_table.m

[Julien Fischer]

On Fri, 19 Aug 2022, Zoltan Somogyi wrote:

> Move var_db and var_{name,type}_source to var_db.m.

...

> diff --git a/compiler/notes/compiler_design.html b/compiler/notes/compiler_design.html
> index 83ea89434..45a048d34 100644
> --- a/compiler/notes/compiler_design.html
> +++ b/compiler/notes/compiler_design.html
> @@ -714,6 +714,13 @@ New code should use var_table.m, if possible.
>  <li>
>  var_table.m defines the data structure that maps each variable
>  to its name, type, and an indication of whether that type is a dummy type.
> +<li>
> +Some modules need to provide functionality
> +both to modules that use var_tables
> +and other modules that use varsets, vartypes, or both.
> +var_db.m defines operations that can provide information
> +about variables' names and/or types
> +that can operate either on top var_tables, or its alternatives.

     on top of

That looks fine otherwise.

Julien.