socketpair shim ICEs if passed a slice as the last argument

The crate `socket` gets the ABI of `socketpair` wrong. It contains a binding that looks like this:
```rust
extern "C" {
    fn socketpair(domain: i32, type_: i32, protocol: i32, sv: *mut [i32]) -> i32;
}

fn main() {
    unsafe {
        socketpair(0, 0, 0, &mut [0] as *mut [i32]);
    }
}
```
This ICEs Miri, instead of reporting UB which is what I'd expect. Should it report UB?