MDEV-15101: Stop ANALYZE TABLE from flushing table definition cache

Apply this patch from Percona Server (amended for 10.5):

commit cd7201514fee78aaf7d3eb2b28d2573c76f53b84
Author: Laurynas Biveinis <laurynas.biveinis@gmail.com>
Date:   Tue Nov 14 06:34:19 2017 +0200

    Fix bug 1704195 / 87065 / TDB-83 (Stop ANALYZE TABLE from flushing table definition cache)

    Make ANALYZE TABLE stop flushing affected tables from the table
    definition cache, which has the effect of not blocking any subsequent
    new queries involving the table if there's a parallel long-running
    query:

    - new table flag HA_ONLINE_ANALYZE, return it for InnoDB and TokuDB
      tables;
    - in mysql_admin_table, if we are performing ANALYZE TABLE, and the
      table flag is set, do not remove the table from the table
      definition cache, do not invalidate query cache;
    - in partitioning handler, refresh the query optimizer statistics
      after ANALYZE if the underlying handler supports HA_ONLINE_ANALYZE;
    - new testcases main.percona_nonflushing_analyze_debug,
      parts.percona_nonflushing_abalyze_debug and a supporting debug sync
      point.

    For TokuDB, this change exposes bug TDB-83 (Index cardinality stats
    updated for handler::info(HA_STATUS_CONST), not often enough for
    tokudb_cardinality_scale_percent). TokuDB may return different
    rec_per_key values depending on dynamic variable
    tokudb_cardinality_scale_percent value. The server does not have a way
    of knowing that changing this variable invalidates the previous
    rec_per_key values in any opened table shares, and so does not call
    info(HA_STATUS_CONST) again. Fix by updating rec_per_key for both
    HA_STATUS_CONST and HA_STATUS_VARIABLE. This also forces a re-record
    of tokudb.bugs.db756_card_part_hash_1_pick, with the new output
    seeming to be more correct.

1 files changed, 8 insertions, 1 deletions

diff --git a/sql/sql_admin.cc b/sql/sql_admin.cc
index 03822acf564..71939936da0 100644
--- a/sql/sql_admin.cc
+++ b/sql/sql_admin.cc
@@ -1141,6 +1141,13 @@ send_result_message:
     }
     if (table->table && !table->view)
     {
+      /*
+        Don't skip flushing if we are collecting EITS statistics.
+      */
+      const bool skip_flush=
+        (operator_func == &handler::ha_analyze) && 
+        (table->table->file->ha_table_flags() & HA_ONLINE_ANALYZE) &&
+        !collect_eis;
       if (table->table->s->tmp_table)
       {
         /*
@@ -1150,7 +1157,7 @@ send_result_message:
         if (open_for_modify && !open_error)
           table->table->file->info(HA_STATUS_CONST);
       }
-      else if (open_for_modify || fatal_error)
+      else if ((!skip_flush && open_for_modify) || fatal_error)
       {
         table->table->s->tdc->flush_unused(true);
         /*