Issue #12549: Correct test_platform to not fail when OS X returns 'x86_64'
as the processor type on some Mac systems.  Also fix NameError in fallback
_mac_ver_gestalt function.  And remove out-of-date URL in docs.
diff --git a/Misc/NEWS b/Misc/NEWS
index caa12a6..6bb9f9f 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -56,6 +56,9 @@
 Tests
 -----
 
+- Issue #12549: Correct test_platform to not fail when OS X returns 'x86_64'
+  as the processor type on some Mac systems.
+
 - Avoid failing in test_robotparser when mueblesmoraleda.com is flaky and
   an overzealous DNS service (e.g. OpenDNS) redirects to a placeholder
   Web site.