MDEV-8316: debugger aborting because missing DBUG_RETURN or DBUG_VOID_RETURN macro in function "any_slave_sql_running"

Fix a handful of "return" that should be DBUG_RETURN in sql/rpl_mi.cc.

Follow-up patch to temporarily avoid a sporadic failure in the test
rpl.rpl_000011 due to MDEV-8301.

There is a window during thread exit where the global status is
counted incorrectly - the contribution for the exiting thread is
counted twice. The patch for MDEV-8294 made this window visible to the
test case rpl.rpl_000011, causing it to sporadically fail. Temporarily
silence this with a wait for the expected value; can be removed once
MDEV-8294 is fixed.

MDEV-8212 alter table - failing to ADD PRIMARY KEY IF NOT EXISTS when existing index of same as column name.
        The default name for the primary key is rather 'PRIMARY' instead of the indexed column name.

Add progress info on InnoDB/XtraDB row0merge phase. Note that we
do not know exact number of rounds merge sort needs at start thus
also progress report might not be accurate.

#include <m_string.h> where strnlen() is used

Added test case to show that correct error message is printed when
log file size is too small for big blob.

some duplicate code.

* take into account that example may be NULL
* use example->safe_charset_converter(), copy-paste from
  Item::safe_charset_converter() (example might have its own
  implementation)
* handle the case when the charset doesn't need conversion
  (and return this).

There were some cases where the slave SQL thread could stop without
the pool of parallel replication worker threads being correctly
de-activated.

* add a test when server certificate is verified successfully
* one test with two combinations (instead of two tests)
* verbose tets: make it print what it is doing
* fix the test to work with yassl and no-ssl builds

            keys

Fixed that OPTIMIZE TABLE against MyISAM/Aria table may write uninitialized key
root position for disabled keys.

           semisync plugin and setting rpl_semi_sync_master_enabled

There was race condition between INSTALL PLUGIN and SET. It was caused by a
gap in INSTALL PLUGIN when plugin variables were registered but not fully
initialized. Accessing such variables concurrently may reference uninitialized
memory, specifically sys_var_pluginvar::plugin.

Fixed by initializing sys_var_pluginvar::plugin early, before variable is
registered.

           semisync plugin and setting rpl_semi_sync_master_enabled

Cleanup:
Removed my_intern_plugin_lock() and my_intern_plugin_lock_ci() wrappers. They
were obsoleted by revision f56dd32b.

instead of running them only when ssl is not compiled in

"Range Checked for Each Record" should be only employed when the other
option would be cross-product join (i.e. the other option is so bad that
we hardly risk anything).

Previous logic was: use RCfER if there are no possible quick selects, or
quick select would read > 100 rows. Also, it didn't always work as
expected due to range optimizer changing table->quick_keys and us
looking at sel->quick_keys.

Another angle is that recent versions have enabled use of Join Buffering
in e.g. outer joins. This further reduces the range of cases where RCfER
should be used.

We are still unable to estimate the cost of RCfER with any precision, so
now changing the condition of "no quick select or quick->records> 100"
to a hopefully better condition "no quick select or quick would cost more
than full table scan".

Using --ssl-verify-server-cert and --ssl[-*] implies that
the ssl connection is required. The mysql client will now print an error if ssl
is required, but the server can not handle a ssl connection.

MDEV-7695 MariaDB - ssl - fips: can not connect with --ssl-cipher=DHE-RSA-AES256-SHA - handshake failure

Change 512bit DH key to 1024bit to meet FIPS requirements

Changing the error message to:
 "...from type 'decimal(0,?)/*old*/' to type ' 'decimal(10,7)'..."
So it's now clear that the master data type is OLD decimal.

Removing Item_cache::used_table_map, Item_cache::used_tables() and
Item_cache::set_used_tables(). Using the same inherited from
Item_basic_constant implementations instead.

remove/replace deprecated options

   More fixes to assure the order of queries in the log.

  This test also should be fixed - delay added so the connection
  event doesn't happen before the query.

   Connection event can happen before the query ends. Added a delay to
   confirm the order.

  Fhe GEOMETRY field should be handled just as the BLOB field. So that was fiexed in field_conv.
  One additional bug was found and fixed meanwhile - thet the geometry field subtypes
  should also be merged for UNION command.

  The MYSQL_AUDIT_NOTIFY_CONNECTION_CONNECT() call moved to the login_connection()
  function. So that it'll be invoked in any thread handling mode.

        If the SET PASSWORD query doesn't have the password string,
        the parsing of it can fail. It manifested first in MySQL 5.6 as
        it started to hide password lines sent to the plugins.
        Fixed by checking for that case.

   Symbols like TAB or NEWLINE should be escaped, which was
        forgotten in one place.