MDEV-9215 Detect cmp_type() and result_type() from field_type()

A cleanup: removing members and functions that become unused:
- Item_func_hybrid_field_type::cached_result_type
- sp_map_result_type()

sql/item_func.h

@@ -447,8 +447,6 @@ class Item_func_hybrid_field_type: public Item_hybrid_func
     DBUG_ASSERT((res != NULL) ^ null_value);
     return res;
   }
-protected:
-  Item_result cached_result_type;
 
 public:
   Item_func_hybrid_field_type(THD *thd):

sql/sp_head.cc

@@ -70,28 +70,6 @@ static void reset_start_time_for_sp(THD *thd)
     thd->set_start_time();
 }
 
-Item_result
-sp_map_result_type(enum enum_field_types type)
-{
-  switch (type) {
-  case MYSQL_TYPE_BIT:
-  case MYSQL_TYPE_TINY:
-  case MYSQL_TYPE_SHORT:
-  case MYSQL_TYPE_LONG:
-  case MYSQL_TYPE_LONGLONG:
-  case MYSQL_TYPE_INT24:
-    return INT_RESULT;
-  case MYSQL_TYPE_DECIMAL:
-  case MYSQL_TYPE_NEWDECIMAL:
-    return DECIMAL_RESULT;
-  case MYSQL_TYPE_FLOAT:
-  case MYSQL_TYPE_DOUBLE:
-    return REAL_RESULT;
-  default:
-    return STRING_RESULT;
-  }
-}
-
 
 Item::Type
 sp_map_item_type(enum enum_field_types type)

sql/sp_head.h

@@ -45,9 +45,6 @@
 //#define TYPE_ENUM_FUNCTION  1 #define TYPE_ENUM_PROCEDURE 2 #define
 //TYPE_ENUM_TRIGGER   3 #define TYPE_ENUM_PROXY     4
 
-Item_result
-sp_map_result_type(enum enum_field_types type);
-
 Item::Type
 sp_map_item_type(enum enum_field_types type);