t/04-xs-rpath-darwin.t: Need Darwin 9 minimum

-rpath is not support on toolchain of older Darwin versions.
Fix for test part of issue #410

Author: sevan

t/04-xs-rpath-darwin.t

@@ -14,9 +14,13 @@ BEGIN {
     chdir 't' or die "chdir(t): $!\n";
     unshift @INC, 'lib/';
     use Test::More;
+    my ($osmajmin) = $Config{osvers} =~ /^(\d+\.\d+)/;
     if( $^O ne "darwin" ) {
         plan skip_all => 'Not darwin platform';
     }
+    elsif ($^O eq 'darwin' && $osmajmin < 9) {
+	plan skip_all => 'For OS X Leopard and newer'
+    }
     else {
         plan skip_all => 'Dynaloading not enabled'
             if !$Config{usedl} or $Config{usedl} ne 'define';