branches/zip: buf_LRU_free_block(): When preserving the compressed page of a block, do not release buf_pool->mutex between the time the old control block is removed from buf_pool->page_hash and the new control block is added to it.  Prevent operations on the compressed-only block while calling btr_search_drop_page_hash_index() or page_zip_calc_checksum().
branches/zip: buf_LRU_free_block(): When preserving the compressed page
of a block, do not release buf_pool->mutex between the time the old control
block is removed from buf_pool->page_hash and the new control block is
added to it.  Prevent operations on the compressed-only block while calling
btr_search_drop_page_hash_index() or page_zip_calc_checksum().

buf_LRU_invalidate_tablespace(): Revert the change done in r1223.
buf_pool->zip_mutex will have been released by
buf_LRU_block_remove_hashed_page() when it returns BUF_BLOCK_ZIP_FREE.

davidl-zend/zenddbi,ollie314/server,davidl-zend/zenddbi,flynn1973/mariadb-aix,davidl-zend/zenddbi,ollie314/server,natsys/mariadb_10.2,flynn1973/mariadb-aix,davidl-zend/zenddbi,natsys/mariadb_10.2,ollie314/server,davidl-zend/zenddbi,ollie314/server,natsys/mariadb_10.2,flynn1973/mariadb-aix,flynn1973/mariadb-aix,natsys/mariadb_10.2,davidl-zend/zenddbi,flynn1973/mariadb-aix,flynn1973/mariadb-aix,natsys/mariadb_10.2,natsys/mariadb_10.2,ollie314/server,flynn1973/mariadb-aix,natsys/mariadb_10.2,flynn1973/mariadb-aix,davidl-zend/zenddbi,ollie314/server,ollie314/server,ollie314/server,ollie314/server,flynn1973/mariadb-aix,davidl-zend/zenddbi,ollie314/server,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,slanterns/server,davidl-zend/zenddbi,natsys/mariadb_10.2,davidl-zend/zenddbi,davidl-zend/zenddbi,flynn1973/mariadb-aix,flynn1973/mariadb-aix,ollie314/server