Extend the syntax accepted by the grammar to account for the new create user
and alter user syntax.

- Add calls to wsrep_sync_wait for
  SHOW CREATE DB/PROCEDURE/FUNCTION/TRIGGER/EVENT
  and SHOW PROCEDURE/FUNCTION CODE

Fix remaining issues with wsrep_sync_wait and query cache.

- Fixes misplaced call to invalidate query cache in
  Rows_log_event::do_apply_event().
  Query cache was invalidated too early, and allowed old
  entries to be inserted to the cache.

- Reset thd->wsrep_sync_wait_gtid on query cache hit.
  THD->cleanup_after_query is not called in such cases,
  and thd->wsrep_sync_wait_gtid remained initialized.

- Restore FLUSH commands supported by MariaDB (removed in
the previous commit)
- Adjust test case

Added following:

        FLUSH CLIENT_STATISTICS
        FLUSH INDEX_STATISTICS
        FLUSH TABLE_STATISTICS
        FLUSH THREAD_STATISTICS
        FLUSH USER_STATISTICS

pertaining to USER STATISTICS
https://www.percona.com/doc/percona-server/5.6/diagnostics/user_stats.html

        FLUSH CHANGED_PAGE_BITMAPS

pertaining to changed page tracking.
https://www.percona.com/doc/percona-server/5.6/management/changed_page_tracking.html

Also, added tests for them.

(cherry picked from commit 7efe49010c7f217663f364657090812b4723f426)

Conflicts:
	mysql-test/suite/galera/r/galera_flush.result
	mysql-test/suite/galera/r/galera_flush_gtid.result
	mysql-test/suite/galera/t/galera_flush.test
	sql/sql_parse.cc

The admin commands in question are:
    > OPTIMIZE
    > REPAIR
    > ANALYZE

For LOCAL or NO_WRITE_TO_BINLOG invocations of these commands, ie

    OPTIMIZE LOCAL TABLE <t1>

they are not binlogged as expected.

Also, in addition, they are not executed under TOI.

Hence, they are not propagated to other nodes.

The effect is same as that of wsrep_on=0.

Also added tests for this.

A WSREP_DEBUG for wsrep_register_hton has also been added.

The galera_flush_local test has also been updated for verifying that effects
of  NO_WRITE_TO_BINLOG / LOCAL are equivalent to wsrep_on=0 from wsrep
perspective.

(cherry picked from commit 5065122f94a8002d4da231528a46f8d9ddbffdc2)

Conflicts:
	sql/sql_admin.cc
	sql/sql_reload.cc
	sql/wsrep_hton.cc

- Moves call wsrep_free_status() to THD::cleanup_after_query().
  Wsrep status variables were previously freed only on SHOW STATUS.
- Removes valgrind suppression from mysql-test/valgrind.

Manually merged query cache fixes from
97c02faf0a39dd189eeda4f75fb35bc5db69d541.

my_atomic_add32_explicit on windows
Fixed that server_audit.c also works if one compiles with safemalloc
Fixed compiler warnings

Creating a CONNECT object on client connect and pass this to the working thread which creates the THD.
Split LOCK_thread_count to different mutexes
Added LOCK_thread_start to syncronize threads
Moved most usage of LOCK_thread_count to dedicated functions
Use next_thread_id() instead of thread_id++

Other things:
- Thread id now starts from 1 instead of 2
- Added cast for thread_id as thread id is now of type my_thread_id
- Made THD->host const (To ensure it's not changed)
- Removed some DBUG_PRINT() about entering/exiting mutex as these was already logged by mutex code
- Fixed that aborted_connects and connection_errors_internal are counted in all cases
- Don't take locks for current_linfo when we set it (not needed as it was 0 before)

New capability flags space.
Removed old progress flag, added new one.

as this is used quite often

- Added testing if connection is killed to shortcut reading of connection data
  This will allow us later in 10.2 to do a cleaner shutdown of slaves (less errors in the log)
- Add new status variables: Slaves_connected, Slaves_running and Slave_connections.
- Use MYSQL_SLAVE_NOT_RUN instead of 0 with slave_running.
- Don't print obvious extra warnings to the error log when slave is shut down normally.

The following left in semi-improved state to keep patch size reasonable:
- Field operator new: left thd_alloc(current_thd)
- Sql_alloc operator new: left thd_alloc(thd_get_current_thd())
- Item_args constructors: left thd_alloc(thd)
- Item_func_interval::fix_length_and_dec(): no THD arg, have to call current_thd
- Item_func_dyncol_exists::val_int(): same
- Item_dyncol_get::val_str(): same
- Item_dyncol_get::val_int(): same
- Item_dyncol_get::val_real(): same
- Item_dyncol_get::val_decimal(): same
- Item_singlerow_subselect::fix_length_and_dec(): same

A prerequisite change for:
- MDEV-8093 sql_yacc.yy: add %type create_field for field_spec and column_def
- MDEV-8094 sql_yacc.yy: get rid of the rules "opt_if_not_exists_table_element"
            and "opt_if_exists_table_element"
- MDEV-8095 Split Create_field

Problem is that FLUSH TABLES WITH READ LOCK first blocks threads from
starting new commits, then waits for running commits to complete. But
in-order parallel replication needs commits to happen in a particular
order, so this can easily deadlock.

To fix this problem, this patch introduces a way to temporarily pause
the parallel replication worker threads. Before starting FTWRL, we let
all worker threads complete in-progress transactions, and then
wait. Then we proceed to take the global read lock. Once the lock is
obtained, we unpause the worker threads. Now commits are blocked from
starting by the global read lock, so the deadlock will no longer occur.

Fix : make sure that database name is converted to lowercase in
check_fk_parent_table_access(), if lowercase_table_names !=0

backport mysql parser fixes
0034963fbf199696792491bcb79d5f0731c98804
5948561812bc691bd0c13cf518a3fe77d9daf920

EXPLAIN INSERT ... SELECT tried to use SELECT's execution path. This
caused a collection of problems:
- SELECT_DESCRIBE flag was not put into select_lex->options, which
  means it was not in JOIN::select_options either (except for the first
  member of the UNION).
- This caused UNION members to be executed. They would attempt to write
  join output rows to the output.
- (Actual cause of the crash) second join sibling would call
  result->send_eof() when finished execution. Then,
  Explain_query::print_explain would attempt to write to query output
  again, and cause an assertion due to non-empty query output.

[EXPLAIN] INSERT .. SELECT creates a select_insert object.
select_insert calls handler->start_bulk_insert() during
initialization.

For MyISAM/Aria this requires that a matching call to
handler->end_bulk_insert() call is made.

Regular INSERT .. SELECT accomplishes this by calling either
select_result->send_eof() or select_result->abort_result_set().

EXPLAIN INSERT ... SELECT didn't call either, which resulted in
improper de-initializaiton of handler object. Make it call
abort_result_set(), which invokes handler->end_bulk_insert().

Check if the engine is supported/allowed before replicating the
statement.

Before this, FLUSH TABLES and FLUSH TABLES t1 (REFRESH_TABLES hereafter) were executed locally,
which also had implications for GTID. MySQL async replication does
replicate FLUSH TABLES.

Hence, this commit

a)  Adds REFRESH_TABLES to TOI.

b) Skips LOCK-based REFRESH_TABLES from TOI, ie. FLUSH TABLES WITH READ
LOCK and FLUSH TABLES FOR EXPORT.

c) Executes them after reload_acl_and_cache. This is done since
reload_acl_and_cache checks for thd->locked_tables_mode and does upgrade
of MDL locks accordingly. A failure here means REFRESH_TABLES cannot
run.

    i) This is also important since LOCK TABLES is not replicated in
    galera.

d) Test galera_flush has been modified for

    i) wsrep_replicate_myisam SESSION variable.

    ii) Testing REFRESH_TABLES.

    iii) Testing REFRESH_TABLES + LOCK TABLES.

e) Use different WSREP_TO_ISOLATION_BEGIN for global FLUSH TABLES and FLUSH TABLES <table,>.

- fix for THD::m_digest initialization, according to Raghu

sessions to cover all exclusive MDL locks

Protecting non replicated FLUSH session from brute force aborts

(MDEV-8617: Post-fix for 10.1)
* Reset THD's PS members before returning when node is
not ready
* Add CF_SKIP_WSREP_CHECK flag to COM_STMT_XXX commands
* Skip TO replication of COM_STMT_PREPAREs for MyISAM
* Updated tests

Part 5: Removing calls to current_thd in net_read calls, creating fields,
        query_cache, acl and some other places where thd was available

- Part 3: Adding mem_root to push_back() and push_front()

Other things:
- Added THD as an argument to some partition functions.
- Added memory overflow checking for XML tag's in read_xml()

- Added mem_root to all calls to new Item
- Added private method operator new(size_t size) to Item to ensure that
  we always use a mem_root when creating an item.

This saves use once call to current_thd per Item creation

Added mandatory thd parameter to Item (and all derivative classes) constructor.
Added thd parameter to all routines that may create items.
Also removed "current_thd" from Item::Item. This reduced number of
pthread_getspecific() calls from 290 to 177 per OLTP RO transaction.

(Additional fixes in 10.0-galera branch)
* Reset THD's PS members before returning when node is
not ready.
* Update galera_suspend_slave.test