Add missing RT ticket label.

jnthn · jnthn · commit a74506c8188a · 2015-12-02T23:31:03.000+01:00
diff --git a/S04-phasers/next.t b/S04-phasers/next.t
@@ -156,6 +156,7 @@ plan 16;
     is($str, '01234', 'NEXT {} works in for loop');
 }
 
+# RT #123731
 {
     my $str = '';
     for ^5 {
