Update 5to6-nutshell.rakudoc (#4486)

fix incorrect link destinations. #index-entry_#dispatch_callsame / ditto samewith / callwith do not exist, but sub_callsame sub_samewith sub_callwith do exist

Author: finanalyst

doc/Language/5to6-nutshell.rakudoc

@@ -287,10 +287,10 @@ first $coderef, @values, :k;
 =begin item
 C<&foo;> I<and> C<goto &foo;> I<for re-using the caller's argument
 list / replacing the caller in the call stack>. Raku can use either
-L<C<callsame>|/language/functions#index-entry-dispatch_callsame> for
+L<C<callsame>|/language/functions#sub_callsame> for
 re-dispatching or
-L<C<nextsame>|/language/functions#index-entry-dispatch_nextsame> and
-L<C<nextwith>|/language/functions#index-entry-dispatch_nextwith>, which have no
+L<C<nextsame>|/language/functions#sub_nextsame> and
+L<C<nextwith>|/language/functions#sub_nextwith>, which have no
 exact equivalent in Perl.
 
 =for code :lang<perl>
@@ -310,7 +310,7 @@ multi foo ( Any $n ) {
 multi foo ( Int $n ) {
     say "Int"; callsame;
 };
-foo(3); # /language/functions#index-entry-dispatch_callsame
+foo(3); # /language/functions#sub_callsame
 =end code
 
 =end item