BUG#50312 Warnings for unsafe sub-statement not returned to client

After BUG#36649, warnings for sub-statements are cleared when a 
new sub-statement is started. This is problematic since it suppresses
warnings for unsafe statements in some cases. It is important that we
always give a warning to the client, because the user needs to know
when there is a risk that the slave goes out of sync.
                        
We fixed the problem by generating warning messages for unsafe statements
while returning from a stored procedure, function, trigger or while
executing a top level statement.
                        
We also started checking unsafeness when both performance and log tables are
used. This is necessary after the performance schema which does a distinction
between performance and log tables.

mysql-test/extra/rpl_tests/create_recursive_construct.inc:
  Changed the order of the calls in the procedure because the code
  that checks if a warning message is printed out expects that the
  first statement gives an warning what is not the case for INSERT
  INTO ta$CRC_ARG_level VALUES (47);
mysql-test/suite/binlog/r/binlog_stm_unsafe_warning.result:
  Updated the result file.
mysql-test/suite/binlog/r/binlog_unsafe.result:
  There are several changes here:
          
  (1) - Changed the CREATE PROCEDURE $CRC.
                                  
  (2) - The procedure $CRC was failing and the content of the binlog
        was being printed out, after fix (1) the failure disappeared.
                                  
  (3) - The warning message for unsafeness due to auto-increment collumns was
        changed.
                                  
  (4) - The warning message for unsafeness due to VERSION(), RAND() was changed.
mysql-test/suite/binlog/t/binlog_stm_unsafe_warning.test:
  Tested filters.
mysql-test/suite/binlog/t/binlog_unsafe.test:
  Reenabled the test case binlog_unsafe.
mysql-test/suite/binlog/t/disabled.def:
  Reenabled the test case binlog_unsafe.
mysql-test/suite/rpl/r/rpl_begin_commit_rollback.result:
  Updated the result file.
mysql-test/suite/rpl/r/rpl_non_direct_stm_mixing_engines.result:
  Updated the result file.
mysql-test/suite/rpl/r/rpl_stm_auto_increment_bug33029.result:
  Updated the result file.
sql/sql_class.cc:
  Moved the stmt_accessed_table_flag variable and related information to the
  LEX as we need the variable reset after each statement even inside a stored
  procedure, what did not happen if the information was in the THD.
          
  Changed the routine in the THD::binlog_query that prints the warning
  messages to avoid trying to print them when inside a stored procedure,
  function or trigger.
                          
  Checked for unsafeness when both performance and log tables where used.
  After the introduction of the performance schema, we need to check both.

mysql-test/suite/rpl/r/rpl_stm_auto_increment_bug33029.result

@@ -39,6 +39,8 @@ INSERT INTO t2 VALUES (NULL);
 RETURN i;
 END//
 CALL p1();
+Warnings:
+Note	1592	Unsafe statement written to the binary log using statement format since BINLOG_FORMAT = STATEMENT. Statement is unsafe because it invokes a trigger or a stored function that inserts into an AUTO_INCREMENT column. Inserted values cannot be logged correctly.
 show binlog events from <binlog_start>;
 Log_name	Pos	Event_type	Server_id	End_log_pos	Info
 master-bin.000001	#	Query	#	#	BEGIN
@@ -123,6 +125,8 @@ SELECT * FROM t2;
 id
 DROP TRIGGER tr1;
 CALL p2();
+Warnings:
+Note	1592	Unsafe statement written to the binary log using statement format since BINLOG_FORMAT = STATEMENT. Statement is unsafe because it invokes a trigger or a stored function that inserts into an AUTO_INCREMENT column. Inserted values cannot be logged correctly.
 show binlog events from <binlog_start>;
 Log_name	Pos	Event_type	Server_id	End_log_pos	Info
 master-bin.000001	#	Query	#	#	BEGIN