Code size regression (opt-level=z) after 1.73.0 (~40%)

Code:

#![no_main]
#[no_mangle]
pub fn f(a: i32) -> i32 {
    let mut result = a + a;
    for i in 0..a {
        for j in 0..a {
            if i * j % 2 == 0 && i + j > a / 2 {
                result += i + j;
            }
            for k in 0..a {
                if (i + j + k) % 3 == 0 && (i * j * k) % 2 != 0 {
                    result += k * (i + j);
                }
            }
        }
    }
    result
}

Link: https://godbolt.org/z/cW5KK4ab8

Start with the minimal Rust reproducer in the issue and the linked Godbolt comparison, compiling it with opt-level=z around Rust 1.73.0 and the affected version. Compare the generated code size and inspect compiler changes relevant to the regression. Done means identifying the cause and confirming that the reproducer no longer shows the roughly 40% increase.