Cleanup: Remove unused fts_cache_t::optimize_lock

This has been unused from the very beginning
(mysql/mysql-server@d5e512ae7e37cd1f70c44a3f12205d70b13118ab).

storage/innobase/fts/fts0fts.cc

@@ -286,7 +286,6 @@ fts_cache_destroy(fts_cache_t* cache)
 {
 	rw_lock_free(&cache->lock);
 	rw_lock_free(&cache->init_lock);
-	mutex_free(&cache->optimize_lock);
 	mutex_free(&cache->deleted_lock);
 	mutex_free(&cache->doc_id_lock);
 	os_event_destroy(cache->sync->event);
@@ -623,8 +622,6 @@ fts_cache_create(
 
 	mutex_create(LATCH_ID_FTS_DELETE, &cache->deleted_lock);
 
-	mutex_create(LATCH_ID_FTS_OPTIMIZE, &cache->optimize_lock);
-
 	mutex_create(LATCH_ID_FTS_DOC_ID, &cache->doc_id_lock);
 
 	/* This is the heap used to create the cache itself. */

storage/innobase/handler/ha_innodb.cc

@@ -588,7 +588,6 @@ static PSI_mutex_info all_innodb_mutexes[] = {
 	PSI_KEY(flush_list_mutex),
 	PSI_KEY(fts_bg_threads_mutex),
 	PSI_KEY(fts_delete_mutex),
-	PSI_KEY(fts_optimize_mutex),
 	PSI_KEY(fts_doc_id_mutex),
 	PSI_KEY(log_flush_order_mutex),
 	PSI_KEY(hash_table_mutex),

storage/innobase/include/fts0types.h

@@ -131,8 +131,6 @@ struct fts_cache_t {
 					intialization, it has different
 					SYNC level as above cache lock */
 
-	ib_mutex_t	optimize_lock;	/*!< Lock for OPTIMIZE */
-
 	ib_mutex_t	deleted_lock;	/*!< Lock covering deleted_doc_ids */
 
 	ib_mutex_t	doc_id_lock;	/*!< Lock covering Doc ID */

storage/innobase/include/sync0sync.h

@@ -62,7 +62,6 @@ extern mysql_pfs_key_t	fil_system_mutex_key;
 extern mysql_pfs_key_t	flush_list_mutex_key;
 extern mysql_pfs_key_t	fts_bg_threads_mutex_key;
 extern mysql_pfs_key_t	fts_delete_mutex_key;
-extern mysql_pfs_key_t	fts_optimize_mutex_key;
 extern mysql_pfs_key_t	fts_doc_id_mutex_key;
 extern mysql_pfs_key_t	fts_pll_tokenize_mutex_key;
 extern mysql_pfs_key_t	hash_table_mutex_key;

storage/innobase/include/sync0types.h

@@ -307,7 +307,6 @@ enum latch_id_t {
 	LATCH_ID_FLUSH_LIST,
 	LATCH_ID_FTS_BG_THREADS,
 	LATCH_ID_FTS_DELETE,
-	LATCH_ID_FTS_OPTIMIZE,
 	LATCH_ID_FTS_DOC_ID,
 	LATCH_ID_FTS_PLL_TOKENIZE,
 	LATCH_ID_HASH_TABLE_MUTEX,

storage/innobase/sync/sync0debug.cc

@@ -1320,9 +1320,6 @@ sync_latch_meta_init()
 
 	LATCH_ADD_MUTEX(FTS_DELETE, SYNC_FTS_OPTIMIZE, fts_delete_mutex_key);
 
-	LATCH_ADD_MUTEX(FTS_OPTIMIZE, SYNC_FTS_OPTIMIZE,
-			fts_optimize_mutex_key);
-
 	LATCH_ADD_MUTEX(FTS_DOC_ID, SYNC_FTS_OPTIMIZE, fts_doc_id_mutex_key);
 
 	LATCH_ADD_MUTEX(FTS_PLL_TOKENIZE, SYNC_FTS_TOKENIZE,

storage/innobase/sync/sync0sync.cc

@@ -48,7 +48,6 @@ mysql_pfs_key_t	fil_system_mutex_key;
 mysql_pfs_key_t	flush_list_mutex_key;
 mysql_pfs_key_t	fts_bg_threads_mutex_key;
 mysql_pfs_key_t	fts_delete_mutex_key;
-mysql_pfs_key_t	fts_optimize_mutex_key;
 mysql_pfs_key_t	fts_doc_id_mutex_key;
 mysql_pfs_key_t	fts_pll_tokenize_mutex_key;
 mysql_pfs_key_t	hash_table_mutex_key;