In MariaDB, InnoDB tables will always contain DATA_N_SYS_COLS = 3
columns, 2 or 3 of which are present in the clustered index.
We remove the predicate that was added in MySQL 5.7 as part of WL#7682.

InnoDB and XtraDB had redundant assertions for checking that
function parameters that were declared as nonnull were not NULL.

it was supposed to be `*(p-1)` not `*p-1`
(the crash happens if `*p==0`)

in particular, don't search for libjemalloc.a, which is only
needed for tokudb's ftcxx tests, when the tests aren't going
to be built.

`zypper install krb5-devel` installs executables outside of $PATH.
It also installs /etc/profile.d/krb5.sh that is sourced by a new
shell to add the new location to the $PATH. But this doesn't affect
the current shell.

Now decent Linux distros remind the user to run `. /etc/profile`
to reload paths in such a case. SUSE doesn't and for a good reason -
it doesn't work there. Because SUSE sets PROFILEREAD=true in the
environment and /etc/profile does not do anything.

By this point, one should not really expect `unset PROFILEREAD` to help,
and it does not - PROFILEREAD is readonly, and cannot be unset.

Apparently SUSE really *really* wants you to re-login between installing
MariaDB build dependencies and actually running the rpmbuild.

Which we cannot do it buildbot. And it would look very user-un-friendly
in the Build Instructions section of the manual.

So, we work around it - by adding SUSE krb5 path to the search list.

THIS IS SUSEEEEEE!!!

Filter out most common file types from automatic dependency collection.
This makes `make package`  in centos73 VM three times faster

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

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.

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

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

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.

rec_get_offsets() was previously called in a btr_cur_optimistic_update()

* mark columns for binlog before inserting history row

Closes #822

Clarify the error message, use the wording from the manual.

Closes #870

Fix partitioning for trx_id-versioned tables.
`partition by hash`, `range` and others now work.
`partition by system_time` is forbidden.
Currently we cannot use row_start and row_end in `partition by`, because
insertion of versioned field is done by engine's handler, as well as
row_start/row_end's value set up, which is a transaction id -- so it's
also forbidden.

The drawback is that it's now impossible to use `partition by key()`
without parameters for such tables, because it references row_start and
row_end implicitly.

* add handler::vers_can_native()
* drop Table_scope_and_contents_source_st::vers_native()
* drop partition_element::find_engine_flag as unused
* forbid versioning partitioning for trx_id as not supported
* adopt vers tests for trx_id partitioning
* forbid any row_end referencing in `partition by` clauses,
  including implicit `by key()`

Fix SELECT resultset order.

MDEV-15412 For any non-existing transaction ID, AS OF provides the current table contents without a warning

Fail with error on non-existing TRX_ID.

Closes #832