Code size regression iterating an array (opt-level=z) after 1.82.0

Code:

```rust
#![no_main]
#[no_mangle]
pub fn f(a: i32) -> i32 { a + a }

#[no_mangle]
pub fn g(a: [i32; 5]) -> i32 {
    let mut sum = 0;
    let arr = [1, 2, 3, 4, 5];
    for i in a.iter().chain(arr.iter()) {
        sum += i;
    }
    sum
}
```

Link: https://godbolt.org/z/14KM5KnPx