add back documentation that $OLD_PERL_VERSION is an alias for $]

diff --git a/pod/perlvar.pod b/pod/perlvar.pod
index bf3c2fa..a8c77ec 100644 (file)
--- a/pod/perlvar.pod
+++ b/pod/perlvar.pod
@@ -433,6 +433,8 @@ Previously, only child processes received stringified values:
 This happens because you can't really share arbitrary data structures with
 foreign processes.
 
+=item $OLD_PERL_VERSION
+
 =item $]
 X<$]>