The problem is that we cannot insert new record into memory table
when table size exceeds max memory table size.
The fix is to use schema_table_store_record() function which
converts memory table into MyISAM in case of table size exceeding.

Note:
There is no test case for this bug, the reason is that
1. The code  that was added already is checked(i.e. works) with existing tests
2. Correct work of schema_table_store_record() is checked with other test cases
   (information_schema tests)
So new code is fully covered with existing test cases.


sql/mysql_priv.h:
  make schema_table_store_record() function global
sql/sql_acl.cc:
  The problem is that we cannot insert new record into memory table
  when table size exceeds max memory table size.
  The fix is to use schema_table_store_record() function which
  converts memory table into MyISAM in case of table size exceeding.
sql/sql_show.cc:
  make schema_table_store_record() function global