used TL_WRITE_CONCURRENT_INSERT though they may update/delete a row. This could cause concurrent SELECTs
to see a changing table while the SELECT happens, or if the query was made of a group of SELECTs,
some SELECTs would see different versions of the table. And anyway versioning in Maria was so far coded
to support only insertions. REPLACE SELECT, INSERT VALUES ON DUPLICATE KEY UPDATE, LOAD DATA REPLACE
were ok.

mysql-test/r/maria2.result:
  result. Without the code fix, the assertion added to ha_maria::update_row() would fire twice.
mysql-test/t/maria2.test:
  test when INSERT ON DUPLICATE KEY UPDATE and LOAD DATA CONCURRENT REPLACE do update rows
storage/maria/ha_maria.cc:
  Assert that update_row and delete_row never see TL_WRITE_CONCURRENT_INSERT.
  INSERT SELECT ON DUPLICATE KEY UPDATE and LOAD DATA CONCURRENT REPLACE
  must upgrade TL_WRITE_CONCURRENT_INSERT to TL_WRITE because they may update/delete a row.