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

On some systems with 10,000+ binlogs, show binary logs could block
log rotation for more than 10 seconds.

This patch fixes this by first caching all binary log names and
releases all mutexes while calculating the sizes of the binary logs.

Other things:
- Ensure that reinit_io_cache() sets end_of_file when moving to read_cache.
  This ensures that external changes of the underlying file is known to
  the cache.
- get_binlog_list() is made more efficent and show_binlogs() is changed
  to call get_binlog_list()

Reviewed by Andrei Elkin

Idea comes from MySQL which does something similar

MariaDB before MDEV-5800 in version 10.2.2 did not support
indexed virtual columns. Non-persistent virtual columns were
hidden from storage engines. Only starting with MDEV-5800, InnoDB
would create internal metadata on virtual columns.

Similar to what was done in MDEV-18084, MDEV-18090, MDEV-18960, we adjust
one more code path for the old tables.

innobase_build_col_map(): Allocate space for virtual columns in col_map[]
but leave the entries at ULINT_UNDEFINED, noting that the virtual columns
were missing before the table was being rebuilt.

InnoDB includes 3 parsers, which use 3 lexical analyzers that
are generated with flex. Flex versions before 2.6 emitted
the keyword "register", which is deprecated in C++17.

The lexical analyzers were regenerated as follows:

for s in storage/innobase storage/xtradb
do
	(cd "$s"/pars; ./make_flex.sh)
	touch "$s"/fts/*.l
	make -C "$s"/fts -f Makefile.query
done

For tablespaces that do not reside on spinning storage, it does
not make sense to attempt to write nearby pages when writing out
dirty pages from the InnoDB buffer pool. It is actually detrimental
to performance and to the life span of flash ROM storage.

With this change, MariaDB will detect whether an InnoDB file resides
on solid-state storage. The detection has been implemented for Linux
and Microsoft Windows. For other systems, we will err on the safe side
and assume that files reside on SSD.

As part of this change, we will reduce the number of fstat() calls
when opening data files on POSIX systems and slightly clean up some
file I/O code.

FIXME: os_is_sparse_file_supported() on POSIX works in a destructive
manner. Thus, we can only invoke it when creating files, not when
opening them.

For diagnostics, we introduce the column ON_SSD to the table
INFORMATION_SCHEMA.INNODB_TABLESPACES_SCRUBBING. The table
INNODB_SYS_TABLESPACES might seem more appropriate, but its purpose
is to reflect the contents of the InnoDB system table SYS_TABLESPACES,
which we would like to remove at some point.

On Microsoft Windows, querying StorageDeviceSeekPenaltyProperty
sometimes returns ERROR_GEN_FAILURE instead of ERROR_INVALID_FUNCTION
or ERROR_NOT_SUPPORTED. We will silently ignore also this error,
and assume that the file does not reside on SSD.

On Linux, the detection will be based on the files
/sys/block/*/queue/rotational and /sys/block/*/dev.
Especially for USB storage, it is possible that
/sys/block/*/queue/rotational will wrongly report 1 instead of 0.

fil_node_t::on_ssd: Whether the InnoDB data file resides on
solid-state storage.

fil_system_t::ssd: Collection of Linux block devices that reside on
non-rotational storage.

fil_system_t::create(): Detect ssd on Linux based on the contents
of /sys/block/*/queue/rotational and /sys/block/*/dev.

fil_system_t::is_ssd(dev_t): Determine if a Linux block device is
non-rotational. Partitions will be identified with the containing
block device by assuming that the least significant 4 bits of the
minor number identify a partition, and that the "partition number"
of the entire device is 0.

The MDEV-11738/MDEV-11581 fix was supposed to add the column
ROTATING_OR_FLUSHING to the INFORMATION_SCHEMA table
INNODB_TABLESPACES_ENCRYPTION, but it also added that column to
INNODB_TABLESPACES_SCRUBBING in InnoDB (not XtraDB).

The extra column was never initialized. We will remove it,
because key rotation has nothing to do with the scrubbing of
tablespace data.

It turns out, moving it to rocksdb_stress test suite is not that easy.

This error occurred when the path to the project contained regular expression characters.

rec_get_offsets() was previously called in a btr_cur_optimistic_update()