Backport the fix for BUG#81810 from facebook/mysql-5.6 tree.
Added the original testcase.

rocksdb.type_text_indexes still fails due to another problem.

- MariaDB produces a warning instead of error when the key
  length is too long
- Trivial test results updates
- rocksdb.rocksdb still fails but this commit makes some progress.

The warning
"ORDER BY ignored as there is a user-defined clustered index in the table 't1'
was missing.

The reason is different condition in copy_data_between_tables():
MariaDB has a change, it uses

  to->file->ha_table_flags() & HA_TABLE_SCAN_ON_INDEX

while MySQL uses:

  to->file->primary_key_is_clustered()).

For some reason, MyRocks didn't have HA_TABLE_SCAN_ON_INDEX flag.
It should have one, will raise that with upstream, too.

rocksdb.lock: LOCK TABLE t1 LOW_PRIORITY WRITE does not produce a
  warining in MariaDB

rocksdb.unique_check:
- MariaDB's mtr prints connection actions
- New (but temporary) ER_LOCK_WAIT_TIMEOUT text

rocksdb.allow_pk_no_concurrent_insert:
- Fix path

rocksdb.locking_issues
- Fix path
- The test still fails but for a different reason now

- Introduce @@rocksdb_supported_compression_types read-only variable.
  It has a comma-separated list of compiled-in compression algorithms.

- Make rocksdb.compression_zstd test skip itself when ZSTD support
  is not compiled in

I've moved it to storage/rocksdb/mysql-test/rocksdb/my.cnf,
but replication tests do not include that file?

Will need to get back to this when getting replication to work

facebook/mysql-5.6 has error messages with extra info, MariaDB doesn't
have extra info:
-ERROR HY000: Lock wait timeout exceeded; try restarting transaction: Timeout on index: test.t1.PRIMARY
+ERROR HY000: Lock wait timeout exceeded; try restarting transaction

This patch updates .result files so that differences do not get in the
way; if we decide to use new error message text in MariaDB, this patch
can be applied in reverse.

- Before this, one had to provide appropriate --mysqld=.... options to
  mysql-test-run.

- Also moved one option from rocksdb/suite.opt to rocksdb/my.cnf.

MySQL's log entries start with log entries like
YYYY-MM-DD 08:25:04 ...
while MariaDB
YYYY-MM-DD  8:25:04 ...

note that '08' turns into ' 8'.
Made grep pattern to account for this.

Copy mysql-test/include/restart_mysqld_with_option.inc from
facebook/mysql-5.6

- Make the same changes as in the previous cset and in
  a cset changing rocksdb.col_opt_null a few csets before.

- MySQL 5.6.11 has fixes for Bug #68472, Bug #16394472, MariaDB doesn't.
  adjust the testcase accordingly.

Make the same changes as with rocksdb.col_opt_null a few csets before:
- MariaDB doesn't provide a default value for non-NULL columns
- Wording in error messages is different
- limits for DECIMAL columns are different
- YEAR(2) is deprecated but still supported

- Also added a --sorted_result for an I_S query.

Based on discussion at maria-developers@:
- Remove 'Support --force-restart "pseudo-argument"'
  that was added a few csets before
- Instead, use "source include/restart_mysqld.inc" in the
  testcases that need a freshly-started server

The differences are due:
- MariaDB 10.1+ assigns different DEFAULT values
  = in some cases, MariaDB's table has no default value, while
    MySQL's has '' as default.
  = BLOB/TEXT can have a default value.
- MariaDB's MTR runs tests with diffferent timezone (affects result of
  FROM_UNIXTIME())
- MySQL has removed YEAR(2). MariaDB produces warning but still creates
  the column of this type.
- Different wording in warning/error messages.

testcases can specify it in *.opt files, it causes the server(s)
to be restarted before running the testcase.

MTRv1 supported this, this patch adds support for MTRv2

- Adjust paths to MyRocks tests
- s/@@dbug/@@debug_dbug/
- etc

A number of tests used to fail due to just not being able to
access MyRocks' I_S plugins:
cons_snapshot_repeatable_read
-drop_table3
-index_file_map
-index_key_block_size
-issue100_delete
-truncate_table3

MySQL has each storage engine to increment Handler_XXX counters,
while MariaDB has handler::ha_XXX() methods to do the increments.

MariaDB's solution doesn't work for storage engines that implement
handler::read_range_first(), though.
Make ha_rocksdb::read_range_first increment the counter (when it is
calling handler::ha_XXX() function that will)

filename_to_tablename() in MariaDB produces warnings when its is
called for temporary file names.
Don't call this function for temporary filename (as we don't need
its result anyway)

Updated test results for obvious MariaDB vs MySQL differences

- MariaDB has different wording for a few error messages
- MySQL changed Extra='' to Extra=NULL for EXPLAIN outputs, MariaDB didnt
- The testsuite in storage/rocksdb/mysql-test needs paths to include
  files adjusted
- In SHOW COLUMNS output, Extra column is "NULL" in MariaDB vs '' in MySQL

Running MTR tests produces an error like this after the test run:

... 140562896741120 [ERROR] Invalid (old?) table or database name '.rocksdb'

There seems to be no way to have the MariaRocks to prevent these, so
the current way to fix them is to have --ignore-db-dirs in my.cnf

SHOW STATUS LIKE 'pattern' returned Rocksdb_XXX status variables
that had SHOW_FUNC type but didn't match the pattern (for example
Rocksdb_block_cache_add).

Among other things, this caused MTR to assume that each testcase
has damaged the execution environment.

The issue was a unitialized variable and then a typo in the condition
that checks if variable name matches the pattern.

In MariaDB, Field::make_sort_key stores NULL-indicator byte for
the field.
In MySQL, it doesn't, so MyRocks stores the NULL-indicator itself.

Switch to using Field::sort_string, which is the same as
Field::make_sort_key in MySQL.

rdb_cf_options.cc must be compiled with RTTI

- Add include/have_rocksdb.inc (TODO: is there any way to have this
  file somewhere under storage/rocksdb/mysql-test ?)
- Make rocksdb.test require have_partition.inc because it uses
  partitioned tables

- Off-by-one error in handler->index_flags() parameter caused
it to be called for the keypart that's after the last key part.

- RocksDB uses RTTI (e.g. it uses dynamic_cast)
- mysql-5.6 has RTTI enabled for the whole server, so there's no
  conflict.
- MariaDB doesn't have RTTI enabled
So the solution is to enable RTTI for
- RocksDB files
- Parts of MyRocks that interface with RocksDB features that require RTTI.

(If one just enables RTTI for all of MyRocks, they will get a
"undefined reference to `typeinfo for handler'" link error)

Also, ER_LOCK_WAIT_TIMEOUT error doesn't have a string parameter
in MariaDB.

Also provide handler::is_using_full_key