misleading printing of value type parameters

`Int32(7)` in `Val{Int32(7)}` is shown as a mere `7`:

```julia-repl
julia> Val{Int32(7)}
Val{7}
```

That's not correct, however, given that `Val{Int32(7)} != Val{7}`.

The misleading printing behavior leads to confusion and complaints such as this one: https://github.com/JuliaArrays/StaticArrays.jl/issues/1233