Get original value in save_post action hooka

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This is the solution:

add_action('pre_post_update', function($post_id, $post_data) {
    global $original_post;

    $original_post = get_post($post_id);
}, 10, 2);

add_action( 'save_post_', function($post_id, $post, $update) {
    global $original_post;

    $original_post->post_title; // original post title
    $post->post_title; // new post title
}, 10, 3);