Removed double records_in_range calls from multi_range_read_info_const

This was to remove a performance regression between 10.3 and 10.4
In 10.5 we will have a better implementation of records_in_range
that will enable us to get more statistics.
This change was not done in 10.4 because the 10.5 will be part of
a larger change that is not suitable for the GA 10.4 version

Other things:
- Changed default handler block_size to 8192 to fix things statistics
  for engines that doesn't set the block size.
- Fixed a bug in spider when using multiple part const ranges
  (Patch from Kentoku)

mysql-test/include/icp_tests.inc

@@ -693,6 +693,7 @@ INSERT INTO t1 VALUES
   ('fkxdmbdkpjdanpje','o'), ('f','Pennsylvan'), ('Virginia','ei');
 
 SET SESSION optimizer_switch='index_condition_pushdown=off';
+--replace_column 9 #
 EXPLAIN
 SELECT * FROM t1 
   WHERE NOT(b = 'Texas') AND b BETWEEN 'wy' AND 'y' OR b = 'Pennsylvania'
@@ -702,6 +703,7 @@ SELECT * FROM t1
   ORDER BY a;
 
 SET SESSION optimizer_switch='index_condition_pushdown=on';
+--replace_column 9 #
 EXPLAIN
 SELECT * FROM t1 
   WHERE NOT(b = 'Texas') AND b BETWEEN 'wy' AND 'y' OR b = 'Pennsylvania'