Mention &*chdir in p5-6 chdir docs

Author: zoffixznet

doc/Language/5to6-perlfunc.pod6

@@ -211,8 +211,11 @@ function that mimics the original Perl 5 behaviour as much as possible.
 Works as it does in Perl 5 but B<must> take an argument.  The behaviour
 of C<chdir()> (with regards to looking at HOME and LOGDIR) is not supported.
 
-In Perl 6, C<chdir> only changes the C<$*CWD> dynamic variable.  It does
-B<not> actually change the default directory from the OS's point of view.
+In Perl 6, L<chdir> only changes the C<$*CWD> dynamic variable.  It does
+B<not> actually change the default directory from the OS's point of view; the
+special dynamic-variable routine L«C<&*chdir>|/routine/&*chdir> can be used
+for that, if needed.
+
 This is done this way, because there is no concept of a "default directory
 per OS thread".  And since Perl 6 does not fork, but only does threading,
 it was felt that the "current directory" concept should be in the C<$*CWD>