** revision-id: vasil.dimov@oracle.com-20140401162003-zfhuxtu710846jd9
  ** committer: Vasil Dimov <vasil.dimov@oracle.com>
  ** branch nick: mysql-trunk
  ** timestamp: Tue 2014-04-01 19:20:03 +0300
  ** message:
  **   Fix Bug#71708 70768 fix perf regression: high rate of RW lock creation
  **   and destruction
  **
  **   Lazily create dict_table_t::stats_latch the first time it is used.
  **   It may not be used at all in the lifetime of some dict_table_t objects.
  **
  **   Approved by:	Bin (rb:4739)