This patch also fixes some bugs detected by valgrind after this
patch:

- Not enough copy_func elements was allocated by Create_tmp_table() which
  causes an memory overwrite in Create_tmp_table::add_fields()
  I added an ASSERT() to be able to detect this also without valgrind.
  The bug was that TMP_TABLE_PARAM::copy_fields was not correctly set
  when calling create_tmp_table().
- Aria::empty_bits is not allocated if there is no varchar/char/blob
  fields in the table.  Fixed code to take this into account.
  This cannot cause any issues as this is just a memory access
  into other Aria memory and the content of the memory would not be used.
- Aria::last_key_buff was not allocated big enough. This may have caused
  issues with rtrees and ma_extra(HA_EXTRA_REMEMBER_POS) as they
  would use the same memory area.
- Aria and MyISAM didn't take extended key parts into account, which
  caused problems when copying rec_per_key from engine to sql level.
- Mark asan builds with 'asan' in version strihng to detect these in
  not_valgrind_build.inc.
  This is needed to not have main.sp-no-valgrind fail with asan.

Nowdays subquery in a UNION's ORDER BY placed correctly in fake select,
the only problem was incorrect Name_resolution_contect is fixed by this
patch in parsing, so we do not need scanning/reseting of ORDER BY of
a union.

When creating a recursive CTE, the column types are taken from the
non recursive part of the CTE (this is according to the SQL standard).

This patch adds code to abort the CTE if the calculated values in the
recursive part does not fit in the fields in the created temporary table.

The new code only affects recursive CTE, so it should not cause any notable
problems for old applications.

Other things:
- Fixed that we get correct row numbers for warnings generated with
  WITH RECURSIVE

Reviewer: Alexander Barkov <bar@mariadb.com>

When creating fields for UNION results, Field_null is not allowed.
Should create binary(0) instead.