Use gen-as-const.py to process .pysym files

[Florian Weimer]

* Joseph Myers:

> +# The output is redirected to a .py file; we'll import it in the
> +# pretty printers file to read the constants generated by
> +# gen-as-const.py.

I would drop the reference to pretty printers here …

> +    elif args.python:
> +        consts = compute_c_consts(sym_data, args.cc)
> +        print('# GENERATED FILE\n'
> +              '\n'
> +              '# Constant definitions for pretty printers.\n'
> +              '# See gen-as-const.py for details.\n')
> +        print('\n'.join('%s = %s' % c for c in sorted(consts.items())))

… and here since the code appears to be generic.

The masking changes look okay to me.

Thanks,
Florian