Mention the clang thread safety analysis.

diff --git a/pod/perldelta.pod b/pod/perldelta.pod
index 82cdff2..dedeca9 100644 (file)
--- a/pod/perldelta.pod
+++ b/pod/perldelta.pod
@@ -369,7 +369,11 @@ well.
 
 =item *
 
-XXX
+Perl core code and the threads extension have been annotated so that
+if Perl is configured to use threads, during compile-time clang (3.6
+or later) will warn about suspicious uses of mutexes.
+See L<http://clang.llvm.org/docs/ThreadSafetyAnalysis.html> for more
+information.
 
 =back