mtr: read both suitedir/disabled.def and suitedir/t/disabled.def

this simplifies merging of MySQL and TokuDB

Author: vuvova

mysql-test/lib/mtr_cases.pm

@@ -498,6 +498,7 @@ sub process_suite {
 
  # disabled.def
  parse_disabled($suite->{dir} .'/disabled.def', $suitename);
+ parse_disabled($suite->{dir} .'/t/disabled.def', $suitename);
 
  # combinations
  if (@::opt_combinations)