Minor optimization cleanup by removing unnecessarycurrent_thdcalls. Bug fixed #1121794 (Alexey Kopytov).
Percona Server would do unnecessary slow log stats accounting even with the slow log disabled. Bug fixed #1123915 (Alexey Kopytov).
Optimization cleanup to avoid calls related to extended slow query log stats when this feature is disabled. Bug fixed #1123921 (Alexey Kopytov).
The staticsrv_pass_corrupt_tablevariable could share CPU cache lines with InnoDB row counters, which resulted in high false sharing effect in high-concurrent workloads. Bug fixed #1125259 (Alexey Kopytov).
Other bug fixes: bug fixed #1089265 (Laurynas Biveinis).