…ource-info-fix, r=oli-obk

Async drop source info fix for proxy-drop-coroutine

Fixes crash at debug info generation: rust-lang#140426 .
Also, the submitted example requires sync Drop implementation too.
Because sync version is required for unwind and when drop is performed in sync context (sync function).

Probably, it is also needed to add such a lint/error about missed `impl Drop`, when there is `impl AsyncDrop`.

Fix description: even minimal, empty coroutine (for proxy-coroutine) has 3 states and the source info array should have 3 elements too.

```
#![feature(async_drop)]

use std::future::AsyncDrop;
use std::pin::Pin;

#[tokio::main(flavor = "current_thread")]
async fn main() {
    let _st = St;
}

struct St;

impl AsyncDrop for St {
    async fn drop(self: Pin<&mut Self>) {
        println!("123");
    }
}
```

Rollup of 3 pull requests

Successful merges:

 - rust-lang#140357 (bypass linker configuration and cross target check on `x check`)
 - rust-lang#140580 (Don't name variables from external macros in borrow errors.)
 - rust-lang#140630 (Async drop source info fix for proxy-drop-coroutine)

r? `@ghost`
`@rustbot` modify labels: rollup

Rollup of 6 pull requests

Successful merges:

 - rust-lang#137280 (stabilize ptr::swap_nonoverlapping in const)
 - rust-lang#140457 (Use target-cpu=z13 on s390x codegen const vector test)
 - rust-lang#140619 (Small adjustments to `check_attribute_safety` to make the logic more obvious)
 - rust-lang#140625 (Suggest `retain_mut` over `retain` as `Vec::extract_if` alternative)
 - rust-lang#140627 (Allow linking rustc and rustdoc against the same single tracing crate)
 - rust-lang#140630 (Async drop source info fix for proxy-drop-coroutine)

r? `@ghost`
`@rustbot` modify labels: rollup

Rollup merge of rust-lang#140630 - azhogin:azhogin/async-drop-proxy-source-info-fix, r=oli-obk

Async drop source info fix for proxy-drop-coroutine

Fixes crash at debug info generation: rust-lang#140426 .
Also, the submitted example requires sync Drop implementation too.
Because sync version is required for unwind and when drop is performed in sync context (sync function).

Probably, it is also needed to add such a lint/error about missed `impl Drop`, when there is `impl AsyncDrop`.

Fix description: even minimal, empty coroutine (for proxy-coroutine) has 3 states and the source info array should have 3 elements too.

```
#![feature(async_drop)]

use std::future::AsyncDrop;
use std::pin::Pin;

#[tokio::main(flavor = "current_thread")]
async fn main() {
    let _st = St;
}

struct St;

impl AsyncDrop for St {
    async fn drop(self: Pin<&mut Self>) {
        println!("123");
    }
}
```