Make parser error/warn message useful

[lysu]

Now parser's error message is useless,
e.g. execute those script:

select1 1;

pingcap/parser will got:

ERROR 1105 (HY000): line 1 column 7 near " 1" (total length 9)

for MySQL will be:

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'select1 1' at line 1

[zz-jason]

@lysu do we still need to process this issue?

[kennytm]

I think it can be closed.

mysql> select1 1;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your TiDB version for the right syntax to use line 1 column 7 near "select1 1"
mysql> select version();
+-----------------------------------------+
| version()                               |
+-----------------------------------------+
| 5.7.25-TiDB-v4.0.0-alpha-532-ge168fd93f |
+-----------------------------------------+
1 row in set (0.00 sec)