3.6 Missing functions

Greetings all.

Tried to upgrade to 3.6 from 3.5.2 this morning and received errors about a function not existing or being invalid:

Warning: call_user_func_array() expects parameter 1 to be a valid callback, function '_show_post_preview' not found or invalid function name in /home/USER/.../wp-includes/plugin.php on line 406

Warning: Cannot modify header information - headers already sent by (output started at /home/develop/macrumors-web-admin/wp-includes/plugin.php:406) in /home/USER/.../wp-includes/pluggable.php on line 875

Sure enough, it doesn’t exist in 3.6. Along with that, here are some others that were found after manually adding _show_post_preview:

/**
 * Retrieve the format slug for a post
 *
 * @since 3.1.0
 *
 * @param int|object $post A post
 *
 * @return mixed The format if successful. False if no format is set. WP_Error if errors.
 */
function get_post_format( $post = null ) {
        $post = get_post($post);

        if ( ! post_type_supports( $post->post_type, 'post-formats' ) )
                return false;

        $_format = get_the_terms( $post->ID, 'post_format' );

        if ( empty( $_format ) )
                return false;

        $format = array_shift( $_format );

        return ( str_replace('post-format-', '', $format->slug ) );
}

function _show_post_preview() {

        if ( isset($_GET['preview_id']) && isset($_GET['preview_nonce']) ) {
                $id = (int) $_GET['preview_id'];

                if ( false == wp_verify_nonce( $_GET['preview_nonce'], 'post_preview_' . $id ) )
                        wp_die( __('You do not have permission to preview drafts.') );

                add_filter('the_preview', '_set_preview');
        }
}

/**
 * Determines if the specified post is a revision.
 *
 * @package WordPress
 * @subpackage Post_Revisions
 * @since 2.6.0
 *
 * @param int|object $post Post ID or post object.
 * @return bool|int False if not a revision, ID of revision's parent otherwise.
 */
function wp_is_post_revision( $post ) {
        if ( !$post = wp_get_post_revision( $post ) )
                return false;
        return (int) $post->post_parent;
}

/**
 * Gets a post revision.
 *
 * @package WordPress
 * @subpackage Post_Revisions
 * @since 2.6.0
 *
 * @uses get_post()
 *
 * @param int|object $post Post ID or post object
 * @param string $output Optional. OBJECT, ARRAY_A, or ARRAY_N.
 * @param string $filter Optional sanitation filter. @see sanitize_post()
 * @return mixed Null if error or post object if success
 */
function wp_get_post_revision(&$post, $output = OBJECT, $filter = 'raw') {
        $null = null;
        if ( !$revision = get_post( $post, OBJECT, $filter ) )
                return $revision;
        if ( 'revision' !== $revision->post_type )
                return $null;

        if ( $output == OBJECT ) {
                return $revision;
        } elseif ( $output == ARRAY_A ) {
                $_revision = get_object_vars($revision);
                return $_revision;
        } elseif ( $output == ARRAY_N ) {
                $_revision = array_values(get_object_vars($revision));
                return $_revision;
        }

        return $revision;
}

/**
 * Retrieve the autosaved data of the specified post.
 *
 * Returns a post object containing the information that was autosaved for the
 * specified post.
 *
 * @package WordPress
 * @subpackage Post_Revisions
 * @since 2.6.0
 *
 * @param int $post_id The post ID.
 * @return object|bool The autosaved data or false on failure or when no autosave exists.
 */
function wp_get_post_autosave( $post_id ) {

        if ( !$post = get_post( $post_id ) )
                return false;

        $q = array(
                'name' => "{$post->ID}-autosave",
                'post_parent' => $post->ID,
                'post_type' => 'revision',
                'post_status' => 'inherit'
        );

        // Use WP_Query so that the result gets cached
        $autosave_query = new WP_Query;

        add_action( 'parse_query', '_wp_get_post_autosave_hack' );
        $autosave = $autosave_query->query( $q );
        remove_action( 'parse_query', '_wp_get_post_autosave_hack' );

        if ( $autosave && is_array($autosave) && is_object($autosave[0]) )
                return $autosave[0];

        return false;
}

/**
 * Internally used to hack WP_Query into submission.
 *
 * @package WordPress
 * @subpackage Post_Revisions
 * @since 2.6.0
 *
 * @param object $query WP_Query object
 */
function _wp_get_post_autosave_hack( $query ) {
        $query->is_single = false;
}

/**
 * Returns all revisions of specified post.
 *
 * @package WordPress
 * @subpackage Post_Revisions
 * @since 2.6.0
 *
 * @uses get_children()
 *
 * @param int|object $post_id Post ID or post object
 * @return array empty if no revisions
 */
function wp_get_post_revisions( $post_id = 0, $args = null ) {
        if ( ! WP_POST_REVISIONS )
                return array();
        if ( ( !$post = get_post( $post_id ) ) || empty( $post->ID ) )
                return array();

        $defaults = array( 'order' => 'DESC', 'orderby' => 'date' );
        $args = wp_parse_args( $args, $defaults );
        $args = array_merge( $args, array( 'post_parent' => $post->ID, 'post_type' => 'revision', 'post_status' => 'inherit' ) );

        if ( !$revisions = get_children( $args ) )
                return array();
        return $revisions;
}

Is anyone else having these errors? Some of these were found in revision.php but not all. Not a very graceful upgrade.