doc:  PG 12 relnotes, add item - pg_test_fsync fix on Windows
Reported-by: Laurenz Albe
Discussion:
Backpatch-through: 12
@@ -2833,6 +2833,20 @@ Author: Andrew Dunstan <andrew@dunslane.net>
</para>
</listitem>
+ <listitem>
+<!--
+Author: Michael Paquier <michael@paquier.xyz>
+2018-09-14 [0ba06e0bf] Allow concurrent-safe open() and fopen() in frontend
+2018-09-20 [40cfe8606] Enforce translation mode for Windows frontends to text
+-->
+
+ <para>
+ Fix <xref linkend="pgtestfsync"/> to report accurate
+ <literal>open_datasync</literal> durations on
+ <productname>Windows</productname> (Laurenz Albe)
+ </para>
+ </listitem>
+
</itemizedlist>
</sect4>
