Stuart Cook 2fae59ac96
Rollup merge of #144864 - Muscraft:no-source-fixes, r=jieyouxu
No source fixes

This PR started as a fix for a rendering bug that [got noticed in #143661](https://github.com/rust-lang/rust/pull/143661#discussion_r2199109530), but turned into a fix for any rendering bugs related to files with no source.
- Don't add an end column separator after a file with no source
- Add column separator before secondary messages with no source
- Render continuation between no source labels

Before
```
error[E0423]: expected function, tuple struct or tuple variant, found struct `std::collections::HashMap`
   ╭▸ $DIR/multi-suggestion.rs:17:13
   │
LL │     let _ = std::collections::HashMap();
   │             ━━━━━━━━━━━━━━━━━━━━━━━━━━━
   ╭▸ $SRC_DIR/std/src/collections/hash/map.rs:LL:COL
   │
   ╰ note: `std::collections::HashMap` defined here
   ╰╴
note: constructor is not visible here due to private fields
   ╭▸ $SRC_DIR/alloc/src/boxed.rs:LL:COL
   │
   ╰ note: private field
   │
   ╰ note: private field
```

After
```
error[E0423]: expected function, tuple struct or tuple variant, found struct `std::collections::HashMap`
   ╭▸ $DIR/multi-suggestion.rs:17:13
   │
LL │     let _ = std::collections::HashMap();
   │             ━━━━━━━━━━━━━━━━━━━━━━━━━━━
   ╰╴
   ╭▸ $SRC_DIR/std/src/collections/hash/map.rs:LL:COL
   │
   ╰ note: `std::collections::HashMap` defined here
note: constructor is not visible here due to private fields
   ╭▸ $SRC_DIR/alloc/src/boxed.rs:LL:COL
   │
   ├ note: private field
   │
   ╰ note: private field
```

Note: This PR also makes it so `rustc` and `annotate-snippets` match in these cases
2025-08-28 23:10:34 +10:00
..
2025-08-27 20:25:18 +02:00