MDEV-7950 Item_func::type() takes 0.26% in OLTP RO

Step #8: Adding get_mm_tree() in Item_func, Item_func_between,
Item_func_in, Item_equal. This removes one virtual call item->type()
in queries like:
  SELECT * FROM t1 WHERE c BETWEEN const1 AND const2;
  SELECT * FROM t1 WHERE c>const;
  SELECT * FROM t1 WHERE c IN (const_list);

sql/item_cmpfunc.h

@@ -655,6 +655,7 @@ public:
   void add_key_fields(JOIN *join, KEY_FIELD **key_fields,
                       uint *and_level, table_map usable_tables,
                       SARGABLE_PARAM **sargables);
+  SEL_TREE *get_mm_tree(RANGE_OPT_PARAM *param, Item **cond_ptr);
 };
 
 
@@ -1337,6 +1338,7 @@ public:
     { return OPTIMIZE_KEY; }
   void add_key_fields(JOIN *join, KEY_FIELD **key_fields, uint *and_level,
                       table_map usable_tables, SARGABLE_PARAM **sargables);
+  SEL_TREE *get_mm_tree(RANGE_OPT_PARAM *param, Item **cond_ptr);
   virtual void print(String *str, enum_query_type query_type);
   enum Functype functype() const { return IN_FUNC; }
   const char *func_name() const { return " IN "; }
@@ -1927,6 +1929,7 @@ public:
   void add_key_fields(JOIN *join, KEY_FIELD **key_fields,
                       uint *and_level, table_map usable_tables,
                       SARGABLE_PARAM **sargables);
+  SEL_TREE *get_mm_tree(RANGE_OPT_PARAM *param, Item **cond_ptr);
   bool walk(Item_processor processor, bool walk_subquery, uchar *arg);
   Item *transform(Item_transformer transformer, uchar *arg);
   virtual void print(String *str, enum_query_type query_type);

sql/item_func.h

@@ -134,6 +134,7 @@ public:
   COND *build_equal_items(THD *thd, COND_EQUAL *inherited,
                           bool link_item_fields,
                           COND_EQUAL **cond_equal_ref);
+  SEL_TREE *get_mm_tree(RANGE_OPT_PARAM *param, Item **cond_ptr);
   bool eq(const Item *item, bool binary_cmp) const;
   virtual optimize_type select_optimize() const { return OPTIMIZE_NONE; }
   virtual bool have_rev_func() const { return 0; }