item_cmpfunc.cc:
  Pass unicode value as "escape" argument to my_wildcmp
  if a multibyte character set is used.
  For single byte character set nothing has changed:
  native (non-unicode) character code is still passed.

ctype_utf8.result, ctype_utf8.test:
  adding test case


sql/item_cmpfunc.cc:
  Bug#12611: ESCAPE + LIKE do not work when the escape char is a multibyte one
  Pass unicode code instead of native code as
  "escape" argument to my_wildcmp.
mysql-test/t/ctype_utf8.test:
  adding test
mysql-test/r/ctype_utf8.result:
  adding test