Adjust an expr span to account for macros
Fix this erroneous suggestion:
```
error[E0529]: expected an array or slice, found `Vec<{integer}>`
--> /home/gh-compiler-errors/test.rs:2:9
|
2 | let [..] = vec![1, 2, 3];
| ^^^^ pattern cannot match with input type `Vec<{integer}>`
|
help: consider slicing here
--> /home/gh-compiler-errors/rust2/library/alloc/src/macros.rs:50:36
|
50~ $crate::__rust_force_expr!(<[_]>::into_vec(
51+ #[rustc_box]
52+ $crate::boxed::Box::new([$($x),+])
53~ )[..])
```
735969eacd