Bug#33275457: Fix multi-valued index

Patch mysql#3: Multi-value indexes are not used for MEMBER OF combined with OR.

If we have a MEMBER OF predicate that is combined with other predicates
with an OR operator, the range optimizer will not consider MEMBER OF
as a candidate for using an index.

Fixed by adding a case construct for Item_func::MEMBER_OF_FUNC in
get_func_mm_tree().

json_overlaps() and json_contains() already has this type of support.

This is a contribution by Yubao Liu.

Change-Id: I1fd7a78091998437310973b3c24099ad554a58a6

Author: roylyseng

mysql-test/r/hash_join.result

@@ -812,11 +812,11 @@ test.t2	analyze	status	OK
 EXPLAIN FORMAT=tree SELECT t1.col_int_key AS field1, t2.col_int AS field2 FROM t2
 JOIN t1 ON 1 WHERE (CAST("1" AS JSON) MEMBER OF( t1.col_json->'$[*]'));
 EXPLAIN
--> Inner hash join (no condition)  (cost=*** rows=5)
+-> Inner hash join (no condition)  (cost=*** rows=10)
     -> Table scan on t2  (cost=*** rows=5)
     -> Hash
-        -> Filter: json'"1"' member of (cast(json_extract(col_json,_utf8mb4'$[*]') as char(40) array))  (cost=*** rows=1)
-            -> Index lookup on t1 using mv_idx (cast(json_extract(col_json,_utf8mb4'$[*]') as char(40) array)=json'"1"')  (cost=*** rows=1)
+        -> Filter: json'"1"' member of (cast(json_extract(col_json,_utf8mb4'$[*]') as char(40) array))  (cost=*** rows=2)
+            -> Index lookup on t1 using mv_idx (cast(json_extract(col_json,_utf8mb4'$[*]') as char(40) array)=json'"1"')  (cost=*** rows=2)
 
 SELECT t1.col_int_key AS field1, t2.col_int AS field2 FROM t2
 JOIN t1 ON 1 WHERE (CAST("1" AS JSON) MEMBER OF( t1.col_json->'$[*]'));