Allow first/last value functions to have frame definitions

Add a test case to check this behavior.

Author: cvicentiu

mysql-test/r/win_first_last_value.result

@@ -657,10 +657,19 @@ class Item_window_func : public Item_func_or_sum
     case Item_sum::PERCENT_RANK_FUNC:
     case Item_sum::CUME_DIST_FUNC:
     case Item_sum::NTILE_FUNC:
+      return true;
+    default: 
+      return false;
+    }
+  }
+
+  bool requires_special_cursors() const
+  {
+    switch (window_func()->sum_func()) {
     case Item_sum::FIRST_VALUE_FUNC:
     case Item_sum::LAST_VALUE_FUNC:
       return true;
-    default: 
+    default:
       return false;
     }
   }

sql/item_windowfunc.h

@@ -2147,7 +2147,8 @@ void get_window_functions_required_cursors(
       functions can keep the default frame generating code, overwrite it or
       add to it.
     */
-    if (item_win_func->is_frame_prohibited())
+    if (item_win_func->is_frame_prohibited() ||
+        item_win_func->requires_special_cursors())
     {
       add_special_frame_cursors(thd, cursor_manager, item_win_func);
       cursor_managers->push_back(cursor_manager);