base/changelog: Note stabilization of asinh (#14927)

libraries/base/changelog.md

@@ -14,6 +14,9 @@
   * Add `Applicative` (for `K1`), `Semigroup` and `Monoid` instances in
     `GHC.Generics`. (#14849)
 
+  * `asinh` for `Float` and `Double` is now numerical stable in the face of
+    large negative arguments (#14927)
+
 ## 4.11.1.0 *TBA*
   * Bundled with GHC 8.4.2