type bit could have null as its default value

[jackysp]

Please answer these questions before submitting your issue. Thanks!

1. What did you do?
   If possible, provide a recipe for reproducing the error.

CREATE TABLE testAllTypes (
	field_1 BIT NULL DEFAULT NULL
	,field_2 TINYINT NULL DEFAULT NULL
	,field_3 TINYINT UNSIGNED NULL DEFAULT NULL
	,field_4 BIGINT NULL DEFAULT NULL
	,field_5 BIGINT UNSIGNED NULL DEFAULT NULL
	,field_6 MEDIUMBLOB NULL DEFAULT NULL
	,field_7 LONGBLOB NULL DEFAULT NULL
	,field_8 BLOB NULL DEFAULT NULL
	,field_9 TINYBLOB NULL DEFAULT NULL
	,field_10 VARBINARY(255) NULL DEFAULT NULL
	,field_11 BINARY(255) NULL DEFAULT NULL
	,field_12 MEDIUMTEXT NULL DEFAULT NULL
	,field_13 LONGTEXT NULL DEFAULT NULL
	,field_14 TEXT NULL DEFAULT NULL
	,field_15 TINYTEXT NULL DEFAULT NULL
	,field_16 CHAR(255) NULL DEFAULT NULL
	,field_17 NUMERIC NULL DEFAULT NULL
	,field_18 DECIMAL NULL DEFAULT NULL
	,field_19 INTEGER NULL DEFAULT NULL
	,field_20 INTEGER UNSIGNED NULL DEFAULT NULL
	,field_21 INT NULL DEFAULT NULL
	,field_22 INT UNSIGNED NULL DEFAULT NULL
	,field_23 MEDIUMINT NULL DEFAULT NULL
	,field_24 MEDIUMINT UNSIGNED NULL DEFAULT NULL
	,field_25 SMALLINT NULL DEFAULT NULL
	,field_26 SMALLINT UNSIGNED NULL DEFAULT NULL
	,field_27 FLOAT NULL DEFAULT NULL
	,field_28 DOUBLE NULL DEFAULT NULL
	,field_29 DOUBLE PRECISION NULL DEFAULT NULL
	,field_30 REAL NULL DEFAULT NULL
	,field_31 VARCHAR(255) NULL DEFAULT NULL
	,field_32 DATE NULL DEFAULT NULL
	,field_33 TIME NULL DEFAULT NULL
	,field_34 DATETIME NULL DEFAULT NULL
	,field_35 TIMESTAMP NULL DEFAULT NULL
);

2. What did you expect to see?
   No error.

3. What did you see instead?
   ERROR 1067 (42000): Invalid default value for 'field_1'

4. What version of TiDB are you using (tidb-server -V or run select tidb_version(); on TiDB)?
   e04f74b

[birdstorm]

+1 for TiSpark is failing corresponding tests because data cannot be loaded by TiDB.