Rollup merge of #109116 - MaciejWas:add-modifies-receiver-diagn-when-method-not-found, r=petrochenkov

Emit diagnostic when calling methods on the unit type in method chains

Fixes #104204.

What this PR does: If a method is not found somewhere in a call chain, we check if we called earlier a method with signature `(&mut T, ...) -> ()`. If this is the case then we emit a diagnostic message.

For example given input:

```
vec![1, 2, 3].into_iter().collect::<Vec<i32>>().sort_by_key(|i| i).sort();
```

the current output is:
```
error[E0599]: no method named `sort` found for unit type `()` in the current scope
 --> hello.rs:3:72
  |
3 |     vec![1, 2, 3].into_iter().collect::<Vec<i32>>().sort_by_key(|i| i).sort();
  |                                                                        ^^^^ method not found in `()`

```

after this PR it will be:
```
error[E0599]: no method named `sort` found for unit type `()` in the current scope
 --> ./hello.rs:3:72
  |
3 |     vec![1, 2, 3].into_iter().collect::<Vec<i32>>().sort_by_key(|i| i).sort();
  |                                                                        ^^^^ method not found in `()`
  |

note: method `sort_by_key` modifies its receiver in-place, it is not meant to be used in method chains.
 --> ./hello.rs:3:53
  |
3 |     vec![1, 2, 3].into_iter().collect::<Vec<i32>>().sort_by_key(|i| i).sort();
  |                                                     ^^^^^^^^^^^ this call modifies its receiver in-place
```

0 files changed, 0 insertions, 0 deletions