Work around intermittent mkdir failures in testcfg.py

test/simple/testcfg.py

@@ -55,7 +55,10 @@ class SimpleTestCase(test.TestCase):
     except:
       pass
     # make it again.
+    try:
       mkdir(self.tmpdir)
+    except:
+      pass
 
   def BeforeRun(self):
     # delete the whole tmp dir
@@ -64,7 +67,12 @@ class SimpleTestCase(test.TestCase):
     except:
       pass
     # make it again.
+    # intermittently fails on win32, so keep trying
+    while not os.path.exists(self.tmpdir):
+      try:
         mkdir(self.tmpdir)
+      except:
+        pass
   
   def GetLabel(self):
     return "%s %s" % (self.mode, self.GetName())