Document renameat2

winsup/cygwin/release/2.9.0

@@ -6,6 +6,8 @@ What's new:
 - New APIs: pthread_mutex_timedwait, pthread_rwlock_timedrdlock,
 	    pthread_rwlock_timedwrlock.
 
+- New API: renameat2.
+
 
 What changed:
 -------------

winsup/doc/new-features.xml

@@ -17,6 +17,10 @@ New APIs: pthread_mutex_timedwait, pthread_rwlock_timedrdlock,
 pthread_rwlock_timedwrlock.
 </para></listitem>
 
+<listitem><para>
+New API: renameat2.
+</para></listitem>
+
 <listitem><para>
 Improved implementation of &lt;elf.h&gt;.
 </para></listitem>

winsup/doc/posix.xml

@@ -1356,6 +1356,7 @@ also IEEE Std 1003.1-2008 (POSIX.1-2008).</para>
     ptsname_r
     putwc_unlocked
     putwchar_unlocked
+    renameat2			(see chapter "Implementation Notes")
     qsort_r			(see chapter "Implementation Notes")
     quotactl
     rawmemchr
@@ -1671,6 +1672,9 @@ group quotas, no inode quotas, no time constraints.</para>
 <para><function>qsort_r</function> is available in both BSD and GNU flavors,
 depending on whether _BSD_SOURCE or _GNU_SOURCE is defined when compiling.</para>
 
+<para>The Linux-specific function <function>renameat2</function> only
+supports the RENAME_NOREPLACE flag.</para>
+
 <para><function>basename</function> is available in both POSIX and GNU flavors,
 depending on whether libgen.h is included or not.</para>