.files extension is not used by debian packaging, .install is.

Whenever Filesort_tracker has r_loops=0, r_ouptut_rows would be 0, so we should add the value zero
to the member "r_output_rows" explicitly

The warning was introduced by the patch that added
the keyword_sp_verb_clause rule.

Adding keyword_sp_verb_clause into sql_yacc.yy and sql_yacc_ora.yy

This is a partial patch for MDEV-12518 unifying:

- Data types: row_type_body vs field_type_row

Fixing sql_yacc_ora.yy: removing field_type_row adding row_type_body instead

Adjust results for storage_engine tests

Adjust results for tests in non-default suites

Adjust search paths for mariadb_config and make further assignment
conditional

this fixes vcol.upgrade failure

* various cleanups (mostly cosmetic)
* remove useless tests (that were tesing the error condition)
* optimize delete_use_source test (from 6 mins to 50 seconds,
  mainly by removing two huge rollbacks at the end).

single-table deletes only

MDEV-13267 At startup with crash recovery: mtr_t::commit_checkpoint(lsn_t, bool): Assertion `!recv_no_log_write' failed

This is a bogus debug assertion failure that should be possible
starting with MariaDB 10.2.2 (which merged WL#7142 via MySQL 5.7.9).

While generating page-change redo log records is strictly out of the
question during tat certain parts of crash recovery, the
fil_names_clear() is only emitting informational MLOG_FILE_NAME
and MLOG_CHECKPOINT records to guarantee that if the server is killed
during or soon after the crash recovery, subsequent crash recovery
will be possible.

The metadata buffer that fil_names_clear() is flushing to the redo log
is being filled by recv_init_crash_recovery_spaces(), right before
starting to apply redo log, by invoking fil_names_dirty() on every
discovered tablespace for which there are changes to apply.

When it comes to Mariabackup (xtrabackup --prepare), it is strictly out
of the question to generate any redo log whatsoever, because that could
break the restore of incremental backups by causing LSN deviation.
So, the fil_names_dirty() call must be skipped when restoring backups.

recv_recovery_from_checkpoint_start(): Do not invoke fil_names_clear()
when restoring a backup.

mtr_t::commit_checkpoint(): Remove the failing assertion. The only
caller is fil_names_clear(), and it must be called by
recv_recovery_from_checkpoint_start() for normal server startup to be
crash-safe. The debug assertion in mtr_t::commit() will still
catch rogue redo log writes.

Even disabling the ccache on the Debian build didn't always prevent
the Travis build running out of space.

As an alternative strategy, the number of alternative compilers has been
reduced to save space. This additional space has been partially reused
by the ccache.

Debian build specific packages have been removed from other builds.

(10.0+ changes, as specified in the MDEV)

and remove unused variable (compiler warning)

There is an inherent race condition between Mariabackup and the
MariaDB server when the InnoDB redo log is being copied. It is
possible that the tail of the circular redo log is overwriting
the head of the log before Mariabackup gets a chance to read it.
So, we reduce the test to generate less redo log. Also, enable
the test on all supported innodb_page_size.

xtrabackup_copy_log(), xtrabackup_copy_logfile():
Change the Boolean parameter to an enum, with the values
COPY_FIRST, COPY_ONLINE, COPY_LAST.

xtrabackup_copy_log(): Return the latest scanned LSN,
which may be less than the last copied LSN. Remove some
dead code that was duplicating some logic that in 10.2
has been moved to log_group_read_log_seg().

log_copying_thread(): Correct the termination condition.

stop_backup_threads(): Shut down the threads that were
created during backup.

Use GET_STR instead of GET_STR_ALLOC, so that the memory will
cannot be leaked. For some reason, calling my_cleanup_options()
on xb_server_options or xb_client_options would not work.