Please improve the with statement by allowing initialisation

[Paul Backus]

On Wednesday, 12 March 2025 at 19:01:46 UTC, Dejan Lekic wrote:
> On Wednesday, 12 March 2025 at 18:55:45 UTC, Dejan Lekic wrote:
>> the with block. Since with statement does not allow 
>> initialisation one would try:
>
> As usual, I forgot to give an example of what I am actually 
> asking for...
>
> ```d
> auto app = new Application();
> with (auto win = new Window) { // currently not allowed
>   setTitle("Example");
>   setDefaultSize(200, 200);
>   setChild(mainBox);
>   app.addWindow(win);
> }
> ```

Seems like a totally uncontroversial change to me. We already 
allow using a declaration in `if`, `while`, and `switch` 
statements; there's no reason `with` shouldn't work the same way.