bpo-35967 resolve platform.processor late (GH-12239)

* Replace flag-flip indirection with direct inspection

* Use any for simpler code

* Avoid flag flip and set results directly.

* Resolve processor in a single function.

* Extract processor handling into a namespace (class)

* Remove _syscmd_uname, unused

* Restore platform.processor behavior to match prior expectation (reliant on uname -p in a subprocess).

* Extract '_unknown_as_blank' function.

* Override uname_result to resolve the processor late.

* Add a test intended to capture the expected values from 'uname -p'

* Instead of trying to keep track of all of the possible outputs on different systems (probably a fool's errand), simply assert that except for the known platform variance, uname().processor matches the output of 'uname -p'

* Use a skipIf directive

* Use contextlib.suppress to suppress the error. Inline strip call.

* 📜🤖 Added by blurb_it.

* Remove use of contextlib.suppress (it would fail with NameError if it had any effect). Rely on _unknown_as_blank to replace unknown with blank.

Co-authored-by: blurb-it[bot] <blurb-it[bot]@users.noreply.github.com>

Lib/test/test_platform.py

@@ -4,7 +4,6 @@ import subprocess
 import sys
 import unittest
 import collections
-import contextlib
 from unittest import mock
 
 from test import support
@@ -168,12 +167,8 @@ class PlatformTest(unittest.TestCase):
         On some systems, the processor must match the output
         of 'uname -p'. See Issue 35967 for rationale.
         """
-        with contextlib.suppress(subprocess.CalledProcessError):
-            expect = subprocess.check_output(['uname', '-p'], text=True).strip()
-
-        if expect == 'unknown':
-            expect = ''
-
+        proc_res = subprocess.check_output(['uname', '-p'], text=True).strip()
+        expect = platform._unknown_as_blank(proc_res)
         self.assertEqual(platform.uname().processor, expect)
 
     @unittest.skipUnless(sys.platform.startswith('win'), "windows only test")