Closes #10618
Closes #16382

Closes #10618
Closes #16382

…eykril

Add `to_path_buf()` method for `RelPath`

There seems to be no ergonomic way to obtain a `RelPathBuf` from a corresponding `&RelPath` at the moment, making the latter sort of a dead end.

The `AbsPath` type provides the following:

```rust
impl AbsPath {
    // ...

    /// Equivalent of [`Path::to_path_buf`] for `AbsPath`.
    pub fn to_path_buf(&self) -> AbsPathBuf {
        AbsPathBuf::try_from(self.0.to_path_buf()).unwrap()
    }

    // ...
}
```

So I took the liberty of adding a corresponding equivalent for `RelPath:

```rust
impl RelPath {
    // ...

    /// Equivalent of [`Path::to_path_buf`] for `RelPath`.
    pub fn to_path_buf(&self) -> RelPathBuf {
        RelPathBuf::try_from(self.0.to_path_buf()).unwrap()
    }

    // ...
}
```

(the change is motivated by an outside use of the `ra_ap_paths` crate that would benefit from being able to use `RelPath` and `AbsPath` over `Path`)

fixes rust-lang/rust-clippy#16696

changelog: [`semicolon_inside_block`]: fix false positive in `try`
blocks where moving `;` inside changes the block's return type and
causes type errors.