Added a test case for bug #11167.
sql_select.cc:
  Fixed bug #11167.
  In 4.1 char/varchar fields are limited by 255 characters in
  length that make them longer than 255 bytes in size for such
  character sets as UTF8. The functions store_record_in_cache
  and read_cached_records did not take into account this
  Moreover the code did not take into account that the size
  of the varchar fields in 5.0 can be up to 65535 bytes