plugin_init() works like this:
1. init MyISAM
2. load plugins from mysql.plugin, if it's a MyISAM table
3. init all not initialized plugins
4. all done, if step 2 loaded mysql.plugin,
   otherwise:
5. load plugins from mysql.plugin
6. init all not initialized plugins

now, with --help --verbose, step 3 will not actually
initialize them, and if mysql.plugin is unreadable,
step 6 will try to initialize existing plugins again.
Fix: when skipping initialization because of --help,
change plugin status from PLUGIN_IS_UNINITIALIZED.

unit test for the IO_CACHE bug

While refreshing the IO_CACHE, do not update its parameters (read_pos,
read_end & pos_in_file) if there is nothing left to read.

Currently we support file block sizes 512K-4K.

Do not build optimised power crc32 on bigendian

Part I: Add diagnostics to page allocation if state is not correct
but do not assert if it is incorrect.

information from the page (note that page could be corrupt).

MDEV-9288: Use POWER8 accelerated crc32

Also removed surperflous stdio include.

Analysis: We have reserved ROW_MERGE_RESERVE_SIZE ( = 4) for
encryption key_version. When calculating is there more
space on sort buffer, this value needs to be substracted
from current available space.

10.1 man pages

MDEV-8923: port innodb_buffer_pool_dump_pct from MySQL

WL#6504 InnoDB buffer pool dump/load enchantments

This patch consists of two parts:

1. Dump only the hottest N% of the buffer pool(s)
2. Prevent hogging the server duing BP load

From MySQL - commit b409342c43ce2edb68807100a77001367c7e6b8e

Add testcases for innodb_buffer_pool_dump_pct.

Part of the code authored by Daniel Black.

 - Make accelerated checksum available to InnoDB and XtraDB.
 - Fall back to slice-by-eight if not available. The mode used is printed on startup.
 - Will only build on POWER systems at the moment until CMakeLists are modified
   to only add the crc32_power8/ files when building on POWER.

running MySQL-5.7 unittest/gunit/innodb/ut0crc32-t

Before:

1..2
Using software crc32 implementation, CPU is little-endian
ok 1
Using software crc32 implementation, CPU is little-endian
    normal CRC32: real    0.148006 sec
    normal CRC32: user    0.148000 sec
    normal CRC32: sys     0.000000 sec
big endian CRC32: real    0.144293 sec
big endian CRC32: user    0.144000 sec
big endian CRC32: sys     0.000000 sec
ok 2

After:

1..2
Using POWER8 crc32 implementation, CPU is little-endian
ok 1
Using POWER8 crc32 implementation, CPU is little-endian
    normal CRC32: real    0.008097 sec
    normal CRC32: user    0.008000 sec
    normal CRC32: sys     0.000000 sec
big endian CRC32: real    0.147043 sec
big endian CRC32: user    0.144000 sec
big endian CRC32: sys     0.000000 sec
ok 2

Author CRC32 ASM code: Anton Blanchard <anton@au.ibm.com>
ref: https://github.com/antonblanchard/crc32-vpmsumSigned-off-by: Daniel Black <daniel.black@au.ibm.com>

- Added missning setting of table->rpl_write_set in record_gtid(), required by galera
- Removed output of WSREP_PATCH_VERSION from galera_defaults, as this can change over time
- Limit galera_many_tables_pk and galera_many_tables_nopk to 900, as
  on many systems the default open table limit is 1024

As 10.1 has systemd support, there is no longer need to set
_SYSTEMCTL_SKIP_REDIRECT/SYSTEMD_NO_WRAP.

Extended my_timer_cycles() to support s390.
Some compiler tunings for RHEL/SLES RPM packages on s390.

myisam_recover is only an alias for myisam_recover_options.
Use the option name instead of the alias is more correct.
This also avoids an note about the use of an alias instead of the option
name on every server start.

by C runtime debug check.

Add testcases for innodb_buffer_pool_dump_pct

WL#6504 InnoDB buffer pool dump/load enchantments

This patch consists of two parts:

1. Dump only the hottest N% of the buffer pool(s)
2. Prevent hogging the server duing BP load

From MySQL - commit b409342c43ce2edb68807100a77001367c7e6b8e

no engines that don't support HA_READ_PREV)

Also, fixing compilation warnings in ctype-mb.ic (Windows).

Post-fix: The test case pushed with the fix had each node
acting as slave to the other two nodes with different set
of filters on server_id's. The slave's gtid_slave_pos is
updated after it processes the events received from master
nodes irrespective of whether the events were filtered
or not. Thus, sync_with_master_gtid.inc could unblock even
on filtered events.
As a result, sync_with_master_gtid.inc would fail to block
until the desired changes have been replicated.  Fixed by
simplifying the topology.
Also, modified CHANGE MASTER commands to ignore based
on gtid_domain_id instead of server_id.

Provided IBM System Z have outdated compiler version, which supports gcc sync
builtins but not gcc atomic builtins. It also has weak memory model.

InnoDB attempted to verify if __sync_lock_test_and_set() is available by
checking IB_STRONG_MEMORY_MODEL. This macro has nothing to do with availability
of __sync_lock_test_and_set(), the right one is HAVE_ATOMIC_BUILTINS.

thread_pool_size is auto-sized before my_getopt(). But my_getopt starts from
resetting all options to their default values. So the auto-sized value is lost.

Fixed by moving thread_pool_size auto-sizing after my_getopt().

wsrep.cmake should be included before cpack_rpm.cmake as it defines
WITH_WSREP, required by cpack_rpm.cmake to conditionally include galera
helper tools in server package's requires list.

--with-plugin-name=xxxx
--with-plugins= now uses =AUTO instead of =1