Support declare error code

[max-hoffman]

Support declare error code:

	{
		Name: "create DECLARE HANDLERs",
		SetUpScript: []string{
			`DROP TABLE IF EXISTS t1;`,
			`CREATE TABLE t1 (pk BIGINT PRIMARY KEY);`,
                        `CREATE PROCEDURE proc_named_condition()
BEGIN
	DECLARE a, b INT DEFAULT 1;
    DECLARE cur1 CURSOR FOR SELECT * FROM t1;
    OPEN cur1;
    BEGIN
	DECLARE eof CONDITION FOR 1329;
	DECLARE EXIT HANDLER FOR eof SET a = 2;
		tloop: LOOP
			FETCH cur1 INTO b;
            IF a > 1 THEN
				LEAVE tloop;
            END IF;
		END LOOP;
    END;
    CLOSE cur1;
    SELECT a;
END;`,
		},
		Assertions: []ScriptTestAssertion{
			{
				Query:    "CALL proc_named_condition();",
				Expected: []sql.Row{{2}},
			},
		},
	},

unsupported syntax: declare eof condition for 1329