C2Rust emits Rust that fails borrow-checking for `volatile` + `__sync_add_and_fetch` (E0499: multiple mutable borrows)

[lynae99]

C2Rust generates Rust code that fails to compile when translating a local volatile uint32_t updated via __sync_add_and_fetch.
The generated Rust keeps a &mut atomic_var in a temporary (let fresh0 = &mut atomic_var;) and also performs ptr::write_volatile(&mut atomic_var as *mut u32, ...) in the same expression, causing Rust borrow checker error E0499 (“cannot borrow as mutable more than once at a time”).
Reproducer

#include <stdint.h>

int main(void) {
    volatile uint32_t atomic_var = 777;
    atomic_var = __sync_add_and_fetch(&atomic_var, 1);
    return 0;
}

C2Rust generates code

#![allow(
    dead_code,
    non_camel_case_types,
    non_snake_case,
    non_upper_case_globals,
    unused_assignments,
    unused_mut
)]
#![feature(core_intrinsics)]
pub type __uint32_t = u32;
pub type uint32_t = __uint32_t;
unsafe fn main_0() -> ::core::ffi::c_int {
    let mut atomic_var: uint32_t = 777 as uint32_t;
    let fresh0 = &mut atomic_var;
    let fresh1 = 1 as ::core::ffi::c_int as uint32_t;
    ::core::ptr::write_volatile(
        &mut atomic_var as *mut uint32_t,
        ::core::intrinsics::atomic_xadd_seqcst(fresh0, fresh1) + fresh1,
    );
    return 0 as ::core::ffi::c_int;
}
pub fn main() {
    unsafe { ::std::process::exit(main_0() as i32) }
}

Rust compilation fails with:

error[E0499]: cannot borrow `atomic_var` as mutable more than once at a time

Environment

• c2rust version: v0.21.0
• platform: Ubuntu 24.04
• Rust: nightly-2022-08-08
• Clang version: 17.0.6

[Rua]

This should be fixed in 0.22, because it now takes raw borrows instead.