Provide a dummy definition of WSREP_NNULL.
This was broken in commit b896f60a.

MDEV-18820 Assertion `lock_table_has(trx, index->table, LOCK_IX)' failed in lock_rec_insert_check_and_lock upon INSERT into table with blob key

Don't Ignore Any error during index lookup, And throw duplicate key error
only if error is HA_ERR_FOUND_DUPP_KEY

Test cleanup and fix.

MDEV-18942: Json_writer::add_bool: Conditional jump or move depends on uninitialised value upon fulltext search under optimizer trace

For keyuse of fulltext set the value for null_rejecting to FALSE
as we don't add NOT NULL keys for fulltext keyuses

MDEV-18962: ASAN heap-buffer-overflow in Single_line_formatting_helper::on_add_str with optimizer trace

Fixed a typo

MariaDB does support InnoDB tables with no stored columns.
(They are necessarily empty.)

after commit b5615eff

On Microsoft Windows, InnoDB writes the path separator \ to the
redo log file, while on all other platforms, / is being used.

fil_name_parse(): Normalize the parsed path separators to the
native format. This allows backups or data sets to be portable
between Windows and other systems.

Closes #1225

MDEV-18921 Server crashes in bitmap_bits_set or bitmap_is_set upon UPDATE IGNORE .. FOR PORTION with binary logging

The fix is same as for MDEV-18859: initialize table->rpl_write_set in
FOR PORTION OF case.

MDEV-18859 Server crashes in bitmap_bits_set / pack_row / THD::binlog_write_row upon DELETE .. FOR PORTION with binary logging

rpl_write_set is initialized in TABLE::mark_columns_per_binlog_row_image.
Since we just call use_all_columns for PORTION OF case, no need in
column marking logic here. Instead, initialize table->rpl_write_set in
place.

The main problem was lack of proper QueryArena handling in
`period_setup_conds`. Since mysql_prepare_update/mysql_prepare_delete
are called during `PREPARE` statement, period conditions, should be
allocated on statement query arena.

Another problem is incorrect statement state handling in
period_setup_conds, which led to unexpected mysql_update termination.

* mysql_update: move period_setup_conds() to mysql_prepare_update to
  store conditions in statement's mem_root

* mtr: add period suite to default list, since --ps-protocol is now
  fixed

Fixes bugs:
MDEV-18853 Assertion `0' failed in Protocol::end_statement upon DELETE .. FOR PORTION via prepared statement
MDEV-18852 Server crashes in reinit_stmt_before_use upon UPDATE .. FOR PORTION via prepared statement

Closes #593

instant_alter_column_possible(): Do not support instantaneous removal
of NOT NULL if the table needs to be rebuilt for removing the hidden
FTS_DOC_ID column. This is not ideal and should ultimately be fixed
properly in MDEV-17459.

This basically is a duplicate of MDEV-18219, proving that the
assertion was not relaxed correctly.

dict_index_t::in_instant_init: A debug flag that will only be set in
btr_cur_instant_init_low() in order to suppress the assertion failure
in rec_init_offsets() for that code path only.

MDEV-18503 Assertion `native.length() == binlen' failed in Type_handler_timestamp_common::make_sort_key

Tests for MDEV-18595 Assertion `0' failed in Item_cache_timestamp::val_datetime_packed / Predicant_to_list_comparator::cmp_arg

The patch for MDEV-18240 fixed this problem earlier. Adding tests only.

This is follow-up for commit 619d22dd
to fix the cmake -DWITH_EMBEDDED_SERVER build.

Fixed by adding more rows to a table

Other things:
- Speed up index_merge tests 20% by adding begin/commit around loops that
  generated rows.

Fixed by caching last binary log number used in last_used_log_number

Other things:
- Moved locking of LOCK_log form new_file_impl() to new_file(). This fixed
  a bug where LOCK_log could have been unlocked even if 'need_lock' was
  not set.  Removed not anymore used argument need_lock.
- Made generate_new_name() virtual to simplify the code between
  other logs and binary log.

Reviewed by Andrei Elkin