FAILS USING 5.6 GTID
 Problem: When there are more than one drop temp table in stored function
          or trigger, replication is failing when GTIDs are enabled.

 Analysis: In ROW based replication format, even though CREATE TEMPORARY
           TABLE query is not replicated, DROP TEMPORARY TABLE queries
           are replicated to achieve proper clean up on Slave end (CREATE
           TEMPORARY TABLE query would have executed and replicated when
           the replication format is STATEMENT) by adding 'IF EXISTS'
           clause. When DROP TEMPORARY TABLE query is in a stored function
           along with some DML statements, the binlog equivalent query
           for that function execution will look like
           BEGIN
             DROP TEMP TABLE ...
             ROW EVENT FOR DML 1
             ROW EVENT FOR DML 2
           END
           But when GTIDs are enabled, it is documented that CREATE/DROP
           TEMPORARY TABLE queries are not allowed in Multi Statement
           Transactions because half executed gtid transactions (rolled
           back of these transactions) can leave these temporary tables
           in a bad state.
           In the old code, one DROP TEMPORARY TABLE in a function is
           working fine because the 'DROP TEMP TABLE' is going into
           STMT_CACHE (which does not be wrapped with BEGIN/COMMIT).
           //STMT_CACHE
           GTID_EVENT
           DROP TEMP TABLE ...
           //TRANS_CACHE
           GTID_EVENT
           BEGIN
             ROW EVENT FOR DML 1
             ROW EVENT FOR DML 2
           END

           But if the function contains two 'DROP TEMP TABLE's, both
           of them are going into 'STMT_CACHE' (which does not be wrapped
           with BEGIN/COMMIT) and STMT_CACHE with one gtid_event cannot
           accommodate two separate DROP TEMP TABLE queries. And with above
           Multi Statement Transactions + GTID restriction, we cannot
           add 'BEGIN/COMMIT'.

Fix:  Stored functions and Triggers are also considered as another form of
      Multi Statement Transactions across the server. To maintain gtid
      consistency and to avoid the problems that are mentioned in this bug
      scenario,  CREATE/DROP temp tables are disallowed from stored functions
      and triggers also just like how they were restricted in Multi Statement
      Transactions. Now function execution that has CREATE/DROP TEMP TABLES
      will throw ER_GTID_UNSAFE_CREATE_DROP_TEMPORARY_TABLE_IN_TRANSACTION.
      ("When @@GLOBAL.ENFORCE_GTID_CONSISTENCY = 1, the statements CREATE
        TEMPORARY TABLE and DROP TEMPORARY TABLE can be executed in a
        non-transactional context only, and require that AUTOCOMMIT = 1. These
        statements are not allowed in Functions or Triggers also as they are also
        considered as Multi Statement transaction.)