OPTIMIZE TABLE statement is forbidden from usage in stored procedures/functions.

NOTE: OPTIMIZE TABLE statement can be useful in stored procedures. The idea is
that the user/administrator can create a stored procedure for admin
tasks (optimizing, backing up, etc). This procedure can be scheduled to run
automatically (by mean of internal cron (WL#1034)). So, once we can make this
statement work, it is worth doing it.


mysql-test/r/sp-error.result:
  Results for the test case for Bug#12953 added.
mysql-test/t/sp-error.test:
  Test case for Bug#12953 "Stored procedures: crash if OPTIMIZE TABLE in function" added.
sql/sql_yacc.yy:
  Forbid "OPTIMIZE TABLE" statement from use in stored procedures/functions.