Bug #38883: thd_security_context is not thread safe, crashes?

After-push minor code cleanup for WL 2360: unnecessary external
reference to LOCK_thread_count has been removed from ha_innodb.cc.

storage/innobase/handler/ha_innodb.cc

@@ -40,12 +40,6 @@ have disabled the InnoDB inlining in this file. */
 #include "ha_innodb.h"
 #include <mysql/plugin.h>
 
-#ifndef MYSQL_SERVER
-/* This is needed because of Bug #3596. Let us hope that pthread_mutex_t
-is defined the same in both builds: the MySQL server and the InnoDB plugin. */
-extern pthread_mutex_t LOCK_thread_count;
-#endif /* MYSQL_SERVER */
-
 /** to protect innobase_open_files */
 static pthread_mutex_t innobase_share_mutex;
 /** to force correct commit order in binlog */

storage/innodb_plugin/handler/ha_innodb.cc

@@ -110,9 +110,6 @@ extern "C" {
 # ifndef MYSQL_PLUGIN_IMPORT
 #  define MYSQL_PLUGIN_IMPORT /* nothing */
 # endif /* MYSQL_PLUGIN_IMPORT */
-/* This is needed because of Bug #3596. Let us hope that pthread_mutex_t
-is defined the same in both builds: the MySQL server and the InnoDB plugin. */
-extern MYSQL_PLUGIN_IMPORT pthread_mutex_t LOCK_thread_count;
 
 #if MYSQL_VERSION_ID < 50124
 /* this is defined in mysql_priv.h inside #ifdef MYSQL_SERVER