Rollup merge of #100130 - compiler-errors:erroneous-return-span, r=lcnr

Avoid pointing out `return` span if it has nothing to do with type error

This code:

```rust
fn f(_: String) {}

fn main() {
    let x = || {
        if true {
            return ();
        }
        f("");
    };
}
```

Emits this:
```
   Compiling playground v0.0.1 (/playground)
error[E0308]: mismatched types
 --> src/main.rs:8:11
  |
8 |         f("");
  |           ^^- help: try using a conversion method: `.to_string()`
  |           |
  |           expected struct `String`, found `&str`
  |
note: return type inferred to be `String` here
 --> src/main.rs:6:20
  |
6 |             return ();
  |                    ^^
```

Specifically, that note has nothing to do with the type error in question. This is because the change implemented in #84244 tries to point out the `return` span on _any_ type coercion error within a closure that happens after a `return` statement, regardless of if the error has anything to do with it.

This is really easy to trigger -- just needs a closure (or an `async`) and an early return (or any other form, e.g. `?` operator suffices) -- and super distracting in production codebases. I'm letting #84128 regress because that issue is much harder to fix correctly, and I can re-open that issue after this lands.

As a drive-by, I added a `resolve_vars_if_possible` to the coercion error logic, which leads to some error improvements. Unrelated to the issue above, though.

0 files changed, 0 insertions, 0 deletions