Auto merge of #11900 - Enselic:needless-borrow-drop, r=Manishearth

needless_borrows_for_generic_args: Handle when field operand impl Drop

Before this fix, the lint had a false positive, namely when a reference was taken to a field when the field operand implements a custom Drop. The compiler will refuse to partially move a type that implements Drop, because that would put the type in a weird state.

## False Positive Example (Fixed)

```rs
struct CustomDrop(String);

impl Drop for CustomDrop {
    fn drop(&mut self) {}
}

fn check_str<P: AsRef<str>>(_to: P) {}

fn test() {
    let owner = CustomDrop(String::default());
    check_str(&owner.0); // Don't lint. `owner` can't be partially moved because it impl Drop
}
```

changelog: [`needless_borrows_for_generic_args`]: Handle when field operand impl Drop

0 files changed, 0 insertions, 0 deletions