Pass --core-file option to mysqld when bootstrapping

BitKeeper/etc/ignore:
  Added mysql-test/r/blackhole.log to the ignore list

.bzrignore

@@ -1066,3 +1066,4 @@ vio/test-sslserver
 vio/viotest-ssl
 include/check_abi
 include/mysql_h.ic
+mysql-test/r/blackhole.log

mysql-test/mysql-test-run.pl

@@ -2624,6 +2624,7 @@ sub install_db ($$) {
   mtr_add_arg($args, "--skip-innodb");
   mtr_add_arg($args, "--skip-ndbcluster");
   mtr_add_arg($args, "--tmpdir=.");
+  mtr_add_arg($args, "--core-file");
 
   if ( $opt_debug )
   {