Dispose multiple resources in a single statement

```ts
using(new Camera(), new Camera(), (cameraA, cameraB) => {
outputPicture(cameraA.takePictureSync());
outputPicture(cameraB.takePictureSync());
});
```

Edit: Should be https://github.com/dsherret/using-statement/issues/1#issuecomment-543441851

This is inspired by https://github.com/tc39/proposal-explicit-resource-management

```ts
// avoids leaking `a` or `b` to outer scope
// ensures `b` is disposed before `a` in case `b` depends on `a`
// ensures `a` is disposed even if disposing `b` throws
try (const a = ..., b = ...) {
...
}
```