allow suite.pm to skip combinations that originate from test/include files.

storage/innobase/handler/handler0alter.cc:
  for NEWDATE key_type says unsigned, thus col->prtype says unsigned,
  but field->flags says signed. Use the same flag for value retrieval
  that was used for value storage.

mysql-test/mysql-test-run.pl

@@ -3715,6 +3715,7 @@ sub do_before_run_mysqltest($)
 {
   my $tinfo= shift;
   my $resfile= $tinfo->{result_file};
+  return unless defined $resfile;
 
   # Remove old files produced by mysqltest
   die "unsupported result file name $resfile, stoping" unless