Update cost for hash and cached joins

The old code did not't correctly add TIME_FOR_COMPARE to rows that are
part of the scan that will be compared with the attached where clause.

Now the cost calculation for hash join and full join cache join are
identical except for HASH_FANOUT (10%)

The cost for a join with keys is now also uniform.
The total cost for a using a key for lookup is calculated in one place as:

(cost_of_finding_rows_through_key(records) + records/TIME_FOR_COMPARE)*
record_count_of_previous_row_combinations + startup_cost

startup_cost is the cost of a creating a temporary table (if needed)

Best_cost now includes the cost of comparing all WHERE clauses and also
cost of joining with previous row combinations.

Other things:
- Optimizer trace is now printing the total costs, including testing the
  WHERE clause (TIME_FOR_COMPARE) and comparing with all previous rows.
- In optimizer trace, include also total cost of query together with the
  final join order. This makes it easier to find out where the cost was
  calculated.
- Old code used filter even if the cost for it was higher than not using a
  filter. This is not corrected.
- When rebasing on 10.11, I noticed some changes to access_cost_factor
  calculation. These changes was not picked as the coming changes
  to filtering will make that code obsolete.

mysql-test/main/stat_tables.result

@@ -71,10 +71,10 @@ order by revenue desc;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	region	ALL	PRIMARY	NULL	NULL	NULL	5	Using where; Using temporary; Using filesort
 1	SIMPLE	nation	ref	PRIMARY,i_n_regionkey	i_n_regionkey	5	dbt3_s001.region.r_regionkey	5	
+1	SIMPLE	supplier	ref	PRIMARY,i_s_nationkey	i_s_nationkey	5	dbt3_s001.nation.n_nationkey	1	
 1	SIMPLE	customer	ref	PRIMARY,i_c_nationkey	i_c_nationkey	5	dbt3_s001.nation.n_nationkey	6	
 1	SIMPLE	orders	ref|filter	PRIMARY,i_o_orderdate,i_o_custkey	i_o_custkey|i_o_orderdate	5|4	dbt3_s001.customer.c_custkey	15 (12%)	Using where; Using rowid filter
 1	SIMPLE	lineitem	ref	PRIMARY,i_l_suppkey,i_l_orderkey,i_l_orderkey_quantity	i_l_orderkey	4	dbt3_s001.orders.o_orderkey	4	Using where
-1	SIMPLE	supplier	eq_ref	PRIMARY,i_s_nationkey	PRIMARY	4	dbt3_s001.lineitem.l_suppkey	1	Using where
 select n_name, sum(l_extendedprice * (1 - l_discount)) as revenue
 from customer, orders, lineitem, supplier, nation, region
 where c_custkey = o_custkey and l_orderkey = o_orderkey
@@ -85,7 +85,7 @@ and r_name = 'AMERICA' and o_orderdate >= date '1995-01-01'
 group by n_name
 order by revenue desc;
 n_name	revenue
-PERU	321915.8715
+PERU	321915.87150000007
 ARGENTINA	69817.1451
 set optimizer_switch=@save_optimizer_switch;
 delete from mysql.index_stats;
@@ -178,10 +178,10 @@ order by revenue desc;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	region	ALL	PRIMARY	NULL	NULL	NULL	5	Using where; Using temporary; Using filesort
 1	SIMPLE	nation	ref	PRIMARY,i_n_regionkey	i_n_regionkey	5	dbt3_s001.region.r_regionkey	5	
+1	SIMPLE	supplier	ref	PRIMARY,i_s_nationkey	i_s_nationkey	5	dbt3_s001.nation.n_nationkey	1	
 1	SIMPLE	customer	ref	PRIMARY,i_c_nationkey	i_c_nationkey	5	dbt3_s001.nation.n_nationkey	6	
 1	SIMPLE	orders	ref|filter	PRIMARY,i_o_orderdate,i_o_custkey	i_o_custkey|i_o_orderdate	5|4	dbt3_s001.customer.c_custkey	15 (12%)	Using where; Using rowid filter
 1	SIMPLE	lineitem	ref	PRIMARY,i_l_suppkey,i_l_orderkey,i_l_orderkey_quantity	i_l_orderkey	4	dbt3_s001.orders.o_orderkey	4	Using where
-1	SIMPLE	supplier	eq_ref	PRIMARY,i_s_nationkey	PRIMARY	4	dbt3_s001.lineitem.l_suppkey	1	Using where
 select n_name, sum(l_extendedprice * (1 - l_discount)) as revenue
 from customer, orders, lineitem, supplier, nation, region
 where c_custkey = o_custkey and l_orderkey = o_orderkey
@@ -192,7 +192,7 @@ and r_name = 'AMERICA' and o_orderdate >= date '1995-01-01'
 group by n_name
 order by revenue desc;
 n_name	revenue
-PERU	321915.8715
+PERU	321915.87150000007
 ARGENTINA	69817.1451
 set optimizer_switch=@save_optimizer_switch;
 EXPLAIN select o_year,