test.support: run_unittest(): Implement in terms on TestSuite and friends.

test.support/test/support.py

@@ -4,8 +4,15 @@ import unittest
 TESTFN = '@test'
 
 def run_unittest(*classes):
+    suite = unittest.TestSuite()
     for c in classes:
-        unittest.run_class(c)
+        suite.addTest(c)
+    runner = unittest.TestRunner()
+    result = runner.run(suite)
+    msg = "Ran %d tests" % result.testsRun
+    if result.skippedNum > 0:
+        msg += " (%d skipped)" % result.skippedNum
+    print(msg)
 
 def can_symlink():
     return False