check kinds in lowering

[nikomatsakis]

Currently we check that when you instantiate a struct or trait you supply the right number of parameters, but we don't check that they have the right kind (i.e., type vs lifetime). I added an (ignored) test check_struct_kinds that demonstrates this. It'd be nice to fix this.

To fix it, one would go into chalk-rust/src/lower/mod.rs and look for places where we check the number of parameters, e.g.:

        if args.len() != info.addl_parameter_kinds.len() {
            bail!("wrong number of parameters for associated type (expected {}, got {})",
                  info.addl_parameter_kinds.len(), args.len())
        }

and adapt those to also check that the kinds in args match the kinds of info.addl_parameter_kinds (in that particular case).