MDEV 13679 Enabled sequences to be used in DEFAULT

Other changes done to get this to work:
- Added 'internal_tables' to TABLE object to list which sequence tables
  is needed to use the table.
- Mark any expression using DEFAULT() with LEX->default_used.
  This is needed when deciding if we should open internal sequence
  tables when a table is opened (we don't need to open sequence tables
  if the main table is only used with SELECT).
- Create_and_open_temporary_table() can now also open all internal
  sequence tables.
- Added option MYSQL_LOCK_USE_MALLOC to mysql_lock_tables()
  to force memory allocation to be used with malloc instead of
  memroot.
- Added flag to MYSQL_LOCK to remember if allocation was done with
  malloc or memroot (makes code simpler and safer).
- init_one_table_for_prelocking() now takes argument for what lock to
  use instead of it's a routine or something else.
- Renamed prelocking placeholders to make them more understandable as
  they are now used in more code.
- Changed test in check_lock_and_start_stmt() if found table has correct
  locks. The old test didn't work for tables that has lock
  TL_WRITE_ALLOW_WRITE, which is what sequence tables are using.
- Added VCOL_NOT_VIRTUAL option to ensure that sequence functions can't
  be used with virtual columns
- More sequence tests

sql/temporary_tables.cc

@@ -65,7 +65,8 @@ TABLE *THD::create_and_open_tmp_table(handlerton *hton,
                                       const char *path,
                                       const char *db,
                                       const char *table_name,
-                                      bool open_in_engine)
+                                      bool open_in_engine,
+                                      bool open_internal_tables)
 {
   DBUG_ENTER("THD::create_and_open_tmp_table");
 
@@ -90,6 +91,15 @@ TABLE *THD::create_and_open_tmp_table(handlerton *hton,
 
       /* Free the TMP_TABLE_SHARE. */
       free_tmp_table_share(share, false);
+      DBUG_RETURN(0);
+    }
+
+    /* Open any related tables */
+    if (open_internal_tables && table->internal_tables &&
+        open_and_lock_internal_tables(table, open_in_engine))
+    {
+      drop_temporary_table(table, NULL, false);
+      DBUG_RETURN(0);
     }
   }