Add new utility function, reap_children(), to test_support. This should

be called at the end of each test that spawns children (perhaps it
should be called from regrtest instead?).  This will hopefully prevent
some of the unexplained failures in the buildbots (hppa and alpha)
during tests that spawn children.  The problems were not reproducible.
There were many zombies that remained at the end of several tests.
In the worst case, this shouldn't cause any more problems,
though it may not help either.  Time will tell.

Lib/test/test_commands.py

@@ -5,7 +5,7 @@
 import unittest
 import os, tempfile, re
 
-from test.test_support import TestSkipped, run_unittest
+from test.test_support import TestSkipped, run_unittest, reap_children
 from commands import *
 
 # The module says:
@@ -58,6 +58,7 @@ class CommandTests(unittest.TestCase):
 
 def test_main():
     run_unittest(CommandTests)
+    reap_children()
 
 
 if __name__ == "__main__":