rpl_udf -- Bug#28993 rpl_udf test causes server crash and valgrind
warning in pushbuild
rpl_ndb_circular -- Bug#29233 rpl_ndb_circular fails randomly
ndb_dd_sql_features -- Bug#29102 ndb_dd_sql_features fails in
pushbuild


mysql-test/t/disabled.def:
  Disable randomly failing tests rpl_udf, rpl_ndb_circular, 
  ndb_dd_sql_features