As MySQL character set tests can print results in many character sets
(latin1, utf8-8, sjis, cp932 and others) - its output can be incompatible
with the current locale settings, which makes PERL confuse.

Fix: reset LC_ALL and LC_CTYPE to "C", which is compatible with
any character set.


mysql-test/mysql-test-run.pl:
  Ignore current locale settings, because "mysqltest" output
  can be not compatible with the locale.