bpo-34011: Fixes missing venv files and other tests (GH-9458)

tests/test_bdist.py

@@ -39,6 +39,9 @@ class BuildTestCase(support.TempdirManager,
 
         for name in names:
             subcmd = cmd.get_finalized_command(name)
+            if getattr(subcmd, '_unsupported', False):
+                # command is not supported on this build
+                continue
             self.assertTrue(subcmd.skip_build,
                             '%s should take --skip-build from bdist' % name)
 

tests/test_bdist_wininst.py

@@ -5,6 +5,8 @@ from test.support import run_unittest
 from distutils.command.bdist_wininst import bdist_wininst
 from distutils.tests import support
 
+@unittest.skipIf(getattr(bdist_wininst, '_unsupported', False),
+    'bdist_wininst is not supported in this install')
 class BuildWinInstTestCase(support.TempdirManager,
                            support.LoggingSilencer,
                            unittest.TestCase):