Function persistence

tests/posix_semantics.rs:6–14

()

#[test]
fn persistence() {
    let os_id = {
        let mut shmem = ShmemConf::new().size(4096).create().unwrap();
        shmem.set_owner(false);
        String::from(shmem.get_os_id())
    };
    let mut shmem = ShmemConf::new().os_id(os_id).open().unwrap();
    shmem.set_owner(true);
}

#[test]
fn posix_behavior() {