privilege: execute admin command must have Super_priv.

[winkyao]

What problem does this PR solve?

Fix security bug of admin commands, before this PR, any user can run admin commands. The Schema names, table names are leaked:

mysql> CREATE USER 'testing';
^C
shell> mysql -u testing
mysql> ADMIN SHOW DDL JOBS;
mysql> ADMIN SHOW DDL JOBS 3676;
mysql> ADMIN CANCEL DDL JOBS 3676;

What is changed and how it works?

This PR add privilege checks with admin commands, you can only execute the admin commands with Super_priv.

shell> mysql -h 127.0.0.1 -P4000 -utesting
mysql> ADMIN SHOW DDL JOBS;
ERROR 1105 (HY000): privilege check fail

Check List

Tests

• Unit test

[winoros]

lgtm

[zimulala]

LGTM

[zimulala]

/run-all-tests