LIKE craashed with a pattern having letters in the range 128..255
(e.g. A WITH ACUTE or C WITH CARON) because of wrong cast from
signed char to unsigned int.


mysql-test/r/ctype_cp1250_ch.result:
  Adding test case
mysql-test/t/ctype_cp1250_ch.test:
  Adding test case
strings/ctype-win1250ch.c:
  Fixing wrong cast from "signed char" -> "uint" to
  "signed char" -> "unsigned char" -> uint, to properly
  handle bytes 128..255.