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  And remove out-of-date URL in docs.

Doc/library/platform.rst

@@ -233,9 +233,6 @@ Mac OS Platform
    Entries which cannot be determined are set to ``''``.  All tuple entries are
    strings.
 
-   Documentation for the underlying :cfunc:`gestalt` API is available online at
-   http://www.rgaros.nl/gestalt/.
-
 
 Unix Platforms
 --------------

Lib/platform.py

@@ -765,6 +765,7 @@ def _mac_ver_gestalt():
                    0x2: 'PowerPC',
                    0xa: 'i386'}.get(sysa,'')
 
+    versioninfo=('', '', '')
     return release,versioninfo,machine
 
 def _mac_ver_xml():

Lib/test/test_platform.py

@@ -191,7 +191,7 @@ class PlatformTest(unittest.TestCase):
             self.assertEqual(res[1], ('', '', ''))
 
             if sys.byteorder == 'little':
-                self.assertEqual(res[2], 'i386')
+                self.assertIn(res[2], ('i386', 'x86_64'))
             else:
                 self.assertEqual(res[2], 'PowerPC')
 

Misc/NEWS

@@ -101,6 +101,9 @@ Build
 Tests
 -----
 
+- Issue #12549: Correct test_platform to not fail when OS X returns 'x86_64'
+  as the processor type on some Mac systems.
+
 - Skip network tests when getaddrinfo() returns EAI_AGAIN, meaning a temporary
   failure in name resolution.