Rollup merge of #102708 - TaKO8Ki:improve-eqeq-suggestion, r=estebank

Suggest `==` to wrong assign expr

Given the following code:

```rust
fn main() {
    let x = 3;
    let y = 3;
    if x == x && y = y {
        println!("{}", x);
    }
}
```

Current output is:

```
error[E0308]: mismatched types
 --> src/main.rs:4:18
  |
4 |     if x == x && y = y {
  |                  ^ expected `bool`, found integer

error[E0308]: mismatched types
 --> src/main.rs:4:8
  |
4 |     if x == x && y = y {
  |        ^^^^^^^^^^^^^^^ expected `bool`, found `()`
```

This adds a suggestion:

```diff
error[E0308]: mismatched types
 --> src/main.rs:6:18
  |
6 |     if x == x && y = y {
  |                  ^ expected `bool`, found integer

error[E0308]: mismatched types
 --> src/main.rs:6:8
  |
6 |     if x == x && y = y {
  |        ^^^^^^^^^^^^^^^ expected `bool`, found `()`
  |
+ help: you might have meant to compare for equality
+   |
+ 6 |     if x == x && y == y {
+   |                     +
```

And this fixes a part of #97469

compiler/rustc_hir_analysis/src/check/expr.rs

@@ -1045,6 +1045,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             let rhs_ty = self.check_expr(&rhs);
             let (applicability, eq) = if self.can_coerce(rhs_ty, lhs_ty) {
                 (Applicability::MachineApplicable, true)
+            } else if let ExprKind::Binary(
+                Spanned { node: hir::BinOpKind::And | hir::BinOpKind::Or, .. },
+                _,
+                rhs_expr,
+            ) = lhs.kind
+            {
+                let actual_lhs_ty = self.check_expr(&rhs_expr);
+                (Applicability::MaybeIncorrect, self.can_coerce(rhs_ty, actual_lhs_ty))
             } else {
                 (Applicability::MaybeIncorrect, false)
             };
@@ -1067,9 +1075,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             }
             if eq {
                 err.span_suggestion_verbose(
-                    span,
+                    span.shrink_to_hi(),
                     "you might have meant to compare for equality",
-                    "==",
+                    '=',
                     applicability,
                 );
             }