Update matching_candidates_in_table() to treat all conditions similar

Fixed also that the 'with_found_constraint parameter' to
matching_candidates_in_table() is as documented: It is now true only
if there is a reference to a previous table in the WHERE condition for
the current examined table (as it was originally documented)

Changes in test results:
- Filtered was 25% smaller for some queries (expected).
- Some join order changed (probably because the tables had very few rows).
- Some more table scans, probably because there would be fewer returned
  rows.
- Some tests exposes a bug that if there is more filtered rows, then the
  cost for table scan will be higher. This will be fixed in a later commit.

1 files changed, 1 insertions, 1 deletions

diff --git a/mysql-test/main/join.result b/mysql-test/main/join.result
index 65dccc6b9a3..94d782abd05 100644
--- a/mysql-test/main/join.result
+++ b/mysql-test/main/join.result
@@ -258,7 +258,7 @@ name varchar(255) default NULL,
 PRIMARY KEY  (id)
 ) ENGINE=MyISAM;
 INSERT INTO t2 VALUES (1,'s1'),(2,'s2'),(3,'s3'),(4,'s4'),(5,'s5');
-select t1.*, t2.*  from t1, t2 where t2.id=t1.t2_id limit 2;
+select straight_join t1.*, t2.*  from t2, t1 where t2.id=t1.t2_id limit 2;
 t1_id	t2_id	type	cost_unit	min_value	max_value	t3_id	item_id	id	name
 12	5	Percent	Cost	-1	0	-1	-1	5	s5
 14	4	Percent	Cost	-1	0	-1	-1	4	s4