NEWS: add a ticket reference

2019-12-25 11:37:27 +09:00 · 2019-12-25 11:37:27 +09:00 · 3345eab934
--- a/2
+++ b/2
@ -763,7 +763,7 @@ Fiber::

 File::
  * File.realpath now uses realpath(3) on many platforms, which can
-    significantly improve performance.
+    significantly improve performance. [Feature #15797]

 Hash::
  * Change data structure of small Hash objects. [Feature #15602]