So null merge.

        'CREATE TABLE IF NOT EXISTS ... SELECT' behaviour
BUG#55474, BUG#55499, BUG#55598, BUG#55616 and BUG#55777 are fixed
in this patch too.

This is the 5.1 part.
It implements:
- if the table exists, binlog two events: CREATE TABLE IF NOT EXISTS
  and INSERT ... SELECT

- Insert nothing and binlog nothing on master if the existing object
  is a view. It only generates a warning that table already exists.


mysql-test/r/trigger.result:
  Ather this patch, 'CREATE TABLE IF NOT EXISTS ... SELECT' will not
  insert anything if the creating table already exists and is a view.
sql/sql_class.h:
  Declare virtual function write_to_binlog() for select_insert.
  It's used to binlog 'create select'
sql/sql_insert.cc:
  Implement write_to_binlog();
  Use write_to_binlog() instead of binlog_query() to binlog the statement.
  if the table exists, binlog two events: CREATE TABLE IF NOT EXISTS
  and INSERT ... SELECT
sql/sql_lex.h:
  Declare create_select_start_with_brace and create_select_pos.
  They are helpful for binlogging 'create select'
sql/sql_parse.cc:
  Do nothing on master if the existing object is a view.
sql/sql_yacc.yy:
  Record the relative postion of 'SELECT' in the 'CREATE ...SELECT' statement.
  Record whether there is a '(' before the 'SELECT' clause.

variable assignments

The assert() that is firing is checking if expressions that can't be
null return a NULL when evaluated.
MAKEDATE() function can return NULL if the second argument is 
less then or equal to 0. Thus its nullability depends not only on 
the nullability of its arguments but also on their values.
Fixed by (overoptimistically) setting MAKEDATE() to be nullable 
despite the nullability of its arguments.
Test added.
Had to update one test result to reflect the metadata change.

The server was not checking for errors generated during
the execution of Item::val_xxx() methods when copying
data to the group, order, or distinct temp table's row.
Fixed by extending the copy_funcs() to return an error
code and by checking for that error code on the places
copy_funcs() is called. 
Test case added.

Fixing copyright text.

it couldn't parse the --ssl option.

client/mysql_upgrade.c:
  mysql_upgrade parses its options and passes some of them to the underlying
  tools (mysqlcheck etc). To do this passdown, it reconstructs a
  command-line-suitable text from the my_option object (which
  contains the option's name and option's value). For options
  which expect no parameter, it just had to use the option's name;
  for other options, it had to concatenate the option's name,
  a "=" symbol, and the option's value; it had code to handle
  this latter case, but only for GET_STR options (options taking a
  string as value). But since the work on WL 4738, the --ssl
  option, a GET_BOOL, which used to have no parameter (NO_ARG), can
  now have one (OPT_ARG), so with --ssl we came to the "default"
  label, error. Fixed by constructing the command-line-suitable
  representation for GET_BOOL too. For --ssl it will produce
  --ssl=1 ; for --ssl=0, it will produce --ssl=0.
mysql-test/include/mysql_upgrade_preparation.inc:
  handles requirements of tests which use mysql_upgrade
mysql-test/r/mysql_upgrade_ssl.result:
  result; without the code fix we would get "internal error".
mysql-test/t/mysql_upgrade.test:
  This test has requirements before running; moved them
  to an include file in order to share with mysql_upgrade_ssl.
mysql-test/t/mysql_upgrade_ssl.test:
  test for bug. Couldn't go into mysql_upgrade.test as this new test requires
  SSL support. --force is needed, in case mysql_upgrade.test run before
  (in which case mysql_upgrade_ssl would say that upgrade has already been
  done); --force forces the upgrade in all cases.

This is a performance improvement fix.

Removed the "volatile" property of PFS_events_waits::m_wait_class.
Simplified the code accordingly.

feature

The test for bug no 50939 was put in range.test which isn't such a good idea
since it requires partitioning. Fixed by moving the test case to
partitioning_range.test.

Updated the README file.

                        
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.

Fix by adding "DEPENDS gen_lex_hash" to ADD_CUSTOM_COMMAND(),
so it regenerates lex_hash.h whenever gen_lex_lash changes.

Also, make sql dependent on GenServerSource to avoid concurrent 
generation of lex_hash.h (once for sql , and in parallel for embedded)

Post-merge fix: add missing comma.

           INSERT IGNORE ... SELECT ... UNION SELECT ...

This assert was triggered by INSERT IGNORE ... SELECT. The assert checks that a
statement either sends OK or an error to the client. If the bug was triggered
on release builds, it caused OK to be sent to the client instead of the correct
error message (in this case ER_FIELD_SPECIFIED_TWICE).

The reason the assert was triggered, was that lex->no_error was set to TRUE
during JOIN::optimize() because of IGNORE. This causes all errors to be ignored.
However, not all errors can be ignored. Some, such as ER_FIELD_SPECIFIED_TWICE
will cause the INSERT to fail no matter what. But since lex->no_error was set,
the critical errors were ignored, the INSERT failed and neither OK nor the
error message was sent to the client.

This patch fixes the problem by temporarily turning off lex->no_error in
places where errors cannot be ignored during processing of INSERT ... SELECT.

Test case added to insert.test.