NEWS: merge Range and Regexp being frozen [doc]

NEWS.md

@@ -192,10 +192,6 @@ Outstanding ones only.
             p C.ancestors #=> [C, M1, M2, Object, Kernel, BasicObject]
             ```
 
-* Range
-
-    * All Range objects are frozen. [Feature #15504]
-
 * Thread
 
     * Introduce `Fiber.set_scheduler` for intercepting blocking operations and
@@ -338,10 +334,10 @@ Outstanding ones only.
 
 Excluding feature bug fixes.
 
-* Regexp literals are frozen [[Feature #8948]] [[Feature #16377]]
+* Regexp literals and all Range objects are frozen [[Feature #8948]] [[Feature #16377] [Feature #15504]]
-
     ```ruby
     /foo/.frozen? #=> true
+    (42...).frozen? # => true
     ```
 
 * EXPERIMENTAL: Hash#each consistently yields a 2-element array [[Bug #12706]]