Fix window function expressions such as win_func() <operator> expr.
The problem was found in 2 places.
First, when we have complex expressions containing window functions, we
can only compute their final value _after_ we have computed the window
function's values. These values must be stored within the temporary
table that we are using, before sending them off.
This is done by performing an extra copy_funcs call before the final
end_send() call.

Second, such expressions need to have their inner arguments,
changed such that the references within those arguments point to fields within
the temporary table.
Ex: sum(t.a) over (order by t.b) + sum(t.a) over (order by t.b)
Before this fix, t.a pointed to the original table's a field. In order
to compute the sum function's value correctly, it needs to point to the
copy of this field inside the temp table.
This is done by calling split_sum_func for each argument in the
expression in turn.

The win.test results have also been updated as they contained wrong
values for such a use case.

This makes them behave exactly like CURRENT ROW. Standard specifies
unsigned integer, which includes the value 0.

Expand the win_min_max test to include this kind of frame definitions.

mincore is defined differently in BSD mincore(void *, size_t, char *) vs
linux variant of: mincore(void *, size_t, unsigned char *).
Account for this difference in TokuDB.

- Change the default @@optimizer_switch value
- Adjust the testcases

In some cases the method Window_funcs_sort::setup() did
not build the sequence of sorting keys correctly.

new MariaDB-shared no longer provides or replaces mysql-libs or mariadb-libs

Do not accessing trx->mysql_log_file_name
after transaction end.

Do not use CloseHandle() on thread id. It is not a kernel handle.

Also MDEV-10385 Threadpool refactoring

* update net_field_length() to match the prototype
* various bug fixes in C/C

fix a bad merge

and INSERT ... SELECT.
Added test cases.

Problem was NULL-pointer reference. Fixed by removing unnecessary and not
really working recursive reserver thread lookup.

because it counts number of bytes sent and expects it to be independent
from the database name length

and a couple of collaterals:
* debugging assert in my_valgrind.h
* trivial cleanup in sql_union.cc

fix a race condition in the test

In some cases the function compare_order_elements() erroneously
returned CMP_EQ for not equal elements.

finally removed, after being deprecated since 2005

do not put there *.so symlinks

fixes: federated.federatedx rpl.rpl_sp rpl.rpl_colSize
rpl.rpl_extra_col_slave_innodb rpl.rpl_extra_col_master_innodb
rpl.rpl_udf rpl.rpl_extra_col_slave_myisam rpl.rpl_extra_col_master_myisam

Updated mysqld--help,win.rdiff.

Some compilers are unhappy about mixed struct/class declarations.

Fixed type cast.

Fixed sysvars_server_[not]embedded failure: changed type of
table_open_cache_instances from ulong to uint.

Added casts foratomic operations around tc_active_instances and
tc_contention_warning_reported: needed on some platforms.