Rollup merge of #99480 - miam-miam100:arg-format, r=oli-obk

Rollup merge of #99480 - miam-miam100:arg-format, r=oli-obk

Diagnostic width span is not added when '0$' is used as width in format strings

When the following code is run rustc does not add diagnostic spans for the width argument. Such spans are necessary for a clippy lint that I am currently writing.

```rust
println!("Hello {1:0$}!", 5, "x");
//                 ^^
// Should have a span here
```