Server already has HMT_low/HMT_medium.

gcc_sync.h, solaris.h, generic-msvc.h copied verbatim.

mariabackup fails to builds with PFS disabled. The reason was missing include,
which was included by PFS otherwise.

Running mysqld with innodb-buffer-pool-instances > 1 hangs on startup.

On startup wrong variables was being used to detect number of page cleaner
threads. As a result no threads were actually started. And subsequent code
waits for threads to start forever.

Fixed by using page_cleaner->n_workers, which holds number of page cleaner
threads (0 at startup) instead of srv_n_page_cleaners, which holds number
of requested page cleaner threads (4 by default).

Big endian checksum is needed to workaround 10+ years old bug, where checksum
was calculated incorrectly on big endian hardware. We can still checksum such
tablespaces using software implementation of CRC32.

- make hp_mask an inline function (short and called 16 times)
- Simplify hp_search. Biggest benefit is for doing key lookup
  without a matching row. Matching rows may be a bit slower, but
  is offseted by having hp_mask inlined.

The non-persistent UPDATE_TIME for InnoDB tables was not being
updated consistently at transaction commit.

If a transaction is partly rolled back so that in the end it will
not modify a table that it intended to modify, the update_time will
be updated nevertheless. This will also happen when InnoDB fails
to write an undo log record for the intended modification.

If a transaction is committed internally in InnoDB, instead of
being committed from the SQL interface, then the trx_t::mod_tables
will not be applied to the update_time of the tables.

trx_t::mod_tables: Replace the std::set<dict_table_t*>
with std::map<dict_table_t*,undo_no_t>, so that the very first
modification within the transaction is identified.

trx_undo_report_row_operation(): Update mod_tables for every operation
after the undo log record was successfully written.

trx_rollback_to_savepoint_low(): After partial rollback, erase from
trx_t::mod_tables any tables for which all changes were rolled back.

trx_commit_in_memory(): Tighten some assertions and simplify conditions.
Invoke trx_update_mod_tables_timestamp() if persistent tables were
affected.

trx_commit_for_mysql(): Remove the call to
trx_update_mod_tables_timestamp(), as it is now invoked at the
lower level, in trx_commit_in_memory().

trx_rollback_finish(): Clear mod_tables before invoking trx_commit(),
because the trx_commit_in_memory() would otherwise wrongly process
mod_tables after a full ROLLBACK.

TODO:
- Make get_thd_memroot() inline
  - To do this, we need to reduce dependence of include files, especially
    so that sql_class.h is not depending in item.h

This will make these files easier to maintain in the future.

The Debian packaging build was failing on Travis-CI due to timeouts.
These changes make it faster by skipping less relevant parts of the build,
like the test suite, RocksDB, TokuDB and Mroonga.

Also fix the usage of the 'make -j' flag to not have any spaces as
recommended in an example in the Debian policy.

Based on pull request by Oleg Obleukhov
https://github.com/MariaDB/server/pull/400

- Change interface according to real usage
- Fix comment
- Rename to fn_frm_ext

DROP TABLE now also works on empty or short .frm files

- We don't check constraints when doing delete

Most "new" failures fixed in the following files:
- sql_select.cc
- item.cc
- item_func.cc
- opt_subselect.cc

Other things:
- Allocate udf_handler strings in mem_root
  - Required changes in sql_string.h
- Add mem_root as argument to some new [] calls
- Mark udf_handler strings as thread specific
- Removed some comment blocks with code

Affected tests:
sql_sequence.gtid sql_sequence.replication

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=79887
was fixed in 7.4 and 8.2.

Both of these reached end of life in February 2011
https://www.freebsd.org/releases/Signed-off-by: Daniel Black <daniel@linux.vnet.ibm.com>

Relax a too strict debug assertion, and add a test.

Allow DROP TABLE `#mysql50##sql-...._.` to drop tables that were
being rebuilt by ALGORITHM=INPLACE

NOTE: If the server is killed after the table-rebuilding ALGORITHM=INPLACE
commits inside InnoDB but before the .frm file has been replaced, then
the recovery will involve something else than DROP TABLE.

NOTE: If the server is killed in a true inplace ALTER TABLE commits
inside InnoDB but before the .frm file has been replaced, then we
are really out of luck. To properly handle that situation, we would
need a transactional mysql.ddl_fixup table that directs recovery to
rename or remove files.

prepare_inplace_alter_table_dict(): Use the altered_table->s->table_name
for generating the new_table_name.

table_name_t::part_suffix: The start of the partition name suffix.

table_name_t::dbend(): Return the end of the schema name.

table_name_t::dblen(): Return the length of the schema name, in bytes.

table_name_t::basename(): Return the name without the schema name.

table_name_t::part(): Return the partition name, or NULL if none.

row_drop_table_for_mysql(): Assert for #sql, not #sql-ib.

rec_get_offsets_func(): Relax a bogus debug assertion.
It would fail when we are operating on a copied prefix
of a node pointer record.

row_log_table_apply_op(): Remove references to dict_table_t::n_vcols.
Virtual column information is no longer being written to the log.

row_log_t: Remove the unused fields n_old_col, n_old_vcol.

MDEV-13723: Server crashes in ha_heap::find_unique_row or Assertion `0' failed in st_select_lex_unit::optimize with INTERSECT

With INTERSECT/EXCEPT fact that subquery item of IN/ALL/ANY was not assigned value does not mean that temporary table used for calculating unit is empty (records could be deleted).