Does the compiler remove unreachable code? Compile with `rustc -C opt-level=2 --emit asm remove-unreachable-code.rs`.

remove-unreachable-code.rs

#[no_mangle]
#[inline(never)]
pub fn on_change(x: u32) {
    println!("x is now {}", x);
}

struct X(u32);

impl X {
    fn change(&mut self, y: u32) {
        if self.0 != y {
            self.0 = y;
            on_change(self.0);
        }
    }
}

#[no_mangle]
#[inline(never)]
pub fn experiment() {
    let mut x = X(11111);

    // x is 11111, should enter if.
    x.change(22222);

    // x is now 22222, should not enter if.
    x.change(22222);

    // x is still 22222, should enter if.
    x.change(33333);

    // x is now 33333, should not enter if.
    x.change(33333);

    // this should all be compiled and optimized down to
    // on_change(22222);
    // on_change(33333);
}

fn main() {
    experiment()
}