Bug#52754 Build break in mysql-trunk, performance schema unit test

Tree cleaup after the last major merges in mysql-trunk:

The files sql/lex_hash.h and sql/sql_yacc.h are automatically
generated, and should not be checked in the configuration management system.
These files are now removed.
No changes are required for .bzrignore, which already listed these files
(and similar files in libmysqld/).

The file storage/perfschema/unittest/pfs_timer-t.cc did not build
after the header files refactoring affecting mysql_priv.h
The file now builds properly using sql_priv.h

storage/perfschema/unittest/pfs_timer-t.cc

@@ -13,7 +13,7 @@
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
 
-#include <mysql_priv.h>
+#include <sql_priv.h>
 #include <my_global.h>
 #include <pfs_timer.h>
 #include "my_sys.h"