Rollup merge of #78048 - blyxxyz:e0424-improve-self-placement, r=lcnr

Suggest correct place to add `self` parameter when inside closure

It would incorrectly suggest adding it as a parameter to the closure instead of the containing function.

[For example](https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=1936bcd1e5f981573386e0cee985c3c0):
```
help: add a `self` receiver parameter to make the associated `fn` a method
  |
5 |         let _ = || self&self;
  |                        ^^^^^
```

`DiagnosticMetadata.current_function` is only used for these messages so tweaking its behavior should be ok.

0 files changed, 0 insertions, 0 deletions