MDEV-33407 Parser support for vector indexes

The syntax is

  create table t1 (... vector index (v) ...);

limitation:
* v is a binary string and NOT NULL
* only one vector index per table
* temporary tables are not supported

MDEV-33404 Engine-independent indexes: subtable method

added support for so-called "high level indexes", they are not visible
to the storage engine, implemented on the sql level. For every such
an index in a table, say, t1, the server implicitly creates a second
table named, like, t1#i#05 (where "05" is the index number in t1).
This table has a fixed structure, no frm, not accessible directly,
doesn't go into the table cache, needs no MDLs.

MDEV-33406 basic optimizer support for k-NN searches

for a query like SELECT ... ORDER BY func() optimizer will use
item_func->part_of_sortkey() to decide what keys can be used
to resolve ORDER BY.

let the caller tell init_tmp_table_share() whether the table
should be thread_specific or not.

In particular, internal tmp tables created in the slave thread
are perfectly thread specific

create templates

  thd->alloc<X>(n) to use instead of (X*)thd->alloc(sizeof(X)*n)

and the same for thd->calloc(). By the default the type is char,
so old usage of thd->alloc(size) works too.

This partially reverts 43623f04

Engines have to set ::position() after ::write_row(), otherwise
the server won't be able to refer to the row just inserted.
This is important for high-level indexes.

heap part isn't reverted, so heap doesn't support high-level indexes.
to fix this, it'll need info->lastpos in addition to info->current_ptr

needed to get partitioning and information about
secondary objects

the information about index algorithm was stored in two
places inconsistently split between both.

BTREE index could have key->algorithm == HA_KEY_ALG_BTREE, if the user
explicitly specified USING BTREE or HA_KEY_ALG_UNDEF, if not.

RTREE index had key->algorithm == HA_KEY_ALG_RTREE
and always had key->flags & HA_SPATIAL

FULLTEXT index had  key->algorithm == HA_KEY_ALG_FULLTEXT
and always had key->flags & HA_FULLTEXT

HASH index had key->algorithm == HA_KEY_ALG_HASH or HA_KEY_ALG_UNDEF

long unique index always had key->algorithm == HA_KEY_ALG_LONG_HASH

In this commit:

All indexes except BTREE and HASH always have key->algorithm
set, HA_SPATIAL and HA_FULLTEXT flags are not used anymore (except
for storage to keep frms backward compatible).

As a side effect ALTER TABLE now detects FULLTEXT index renames correctly

Bounded_queue<> pretended to be a typesafe C++ wrapper
on top of pure C queues.h.

But it wasn't, it was tightly bounded to filesort and only useful there.

* implement Queue<> - a typesafe C++ wrapper on top of QUEUE
* move Bounded_queue to filesort.cc, remove pointless "generalizations"
  change it to use Queue.
* remove bounded_queue.h
* change subselect_rowid_merge_engine to use Queue, not QUEUE

as it can never be null (only "" or "disabled")

These variables/parameters have the default read-only value of 1, and
the only way to change them is through a command line flag together
with a command line flag loading spider. After this change, the flag
will have no effect.

           crash recovery

Summary
=======
When doing server recovery, the active transactions will be rolled
back by InnoDB background rollback thread automatically. The
prepared transactions will be committed or rolled back accordingly
by binlog recovery. Binlog recovery is done in main thread before
the server can provide service to users. If there is a big
transaction to rollback, the server will not available for a long
time.

This patch provides a way to rollback the prepared transactions
asynchronously. Thus the rollback will not block server startup.

Design
======
- Handler::recover_rollback_by_xid()
  This patch provides a new handler interface to rollback transactions
  in recover phase. InnoDB just set the transaction's state to active.
  Then the transaction will be rolled back by the background rollback
  thread.

- Handler::signal_tc_log_recover_done()
  This function is called after tc log is opened(typically binlog opened)
  has done. When this function is called, all transactions will be rolled
  back have been reverted to ACTIVE state. Thus it starts rollback thread
  to rollback the transactions.

- Background rollback thread
  With this patch, background rollback thread is defered to run until binlog
  recovery is finished. It is started by innobase_tc_log_recovery_done().

If a slave replicating an event has waited for more than
@@slave_abort_blocking_timeout for a conflicting metadata lock held by a
non-replication thread, the blocking query is killed to allow replication to
proceed and not be blocked indefinitely by a user query.
Reviewed-by: Monty <monty@mariadb.org>
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

The recent commit 4ca355d8 (MDEV-33894)
caused a serious regression for online InnoDB ib_logfile0 resizing,
breaking crash-safety unless the memory-mapped log file interface is
being used. However, the log resizing was broken also before this.

To prevent such regressions in the future, we extend the test
innodb.log_file_size_online with a kill and restart of the server
and with some writes running concurrently with the log size change.
When run enough many times, this test revealed all the bugs that
are being fixed by the code changes.

log_t::resize_start(): Do not allow the resized log to start before
the current log sequence number. In this way, there is no need to
copy anything to the first block of resize_buf. The previous logic
regarding that was incorrect in two ways. First, we would have to
copy from the last written buffer (buf or flush_buf). Second, we failed
to ensure that the mini-transaction end marker bytes would be 1
in the buffer. If the source ib_logfile0 had wrapped around an odd number
of times, the end marker would be 0. This was occasionally observed
when running the test innodb.log_file_size_online.

log_t::resize_write_buf(): To adjust for the resize_start() change,
do not write anything that would be before the resize_lsn.
Take the buffer (resize_buf or resize_flush_buf) as a parameter.
Starting with commit 4ca355d8
we no longer swap buffers when rewriting the last log block.

log_t::append(): Define as a static function; only some debug
assertions need to refer to the log_sys object.

innodb_log_file_size_update(): Wake up the buf_flush_page_cleaner()
if needed, and wait for it to complete a batch while waiting for
the log resizing to be completed. If the current LSN is behind the
resize target LSN, we will write redundant FILE_CHECKPOINT records to
ensure that the log resizing completes. If the buf_pool.flush_list is
empty or the buf_flush_page_cleaner() is stuck for some reason, our wait
will time out in 5 seconds, so that we can periodically check if the
execution of SET GLOBAL innodb_log_file_size was aborted. Previously,
we could get into a busy loop here while the buf_flush_page_cleaner()
would remain idle.

Added missing method of Item_static_float_func

  --quick-max-column-width parameter added to limit field
    width in --quick mode.

recv_recovery_from_checkpoint_start(): Abort startup due to log
corruption if we were unable to parse the entire log between
the latest log checkpoint and the corresponding FILE_CHECKPOINT record.

Also, reduce some code bloat related to log output and log_sys.mutex.

Reviewed by: Debarun Banerjee

The option binlog_optimize_thread_scheduling was initially added
to provide a safe alternative for the newly added binlog group
commit logic, such that when 0, it would disable a leader thread
from performing the binlog write for all transactions that are a
part of the group commit. Any problems related to the binlog group
commit optimization should be sorted out by now, so we can
deprecate-to-eventually-remove the option altogether.

This commit performs the deprecation, and the removal is tracked
by MDEV-33745. Note, as the option is only able to be provided
via configuration at startup time, users will not see a
deprecation message unless looking through the CLI help
message.

Reviewed By
============
Kristian Nielsen <knielsen@knielsen-hq.org>
Sergei Golubchik <serg@mariadb.org>