Run all message tests with a variant that forces preparsing

test/message/testcfg.py

Index: test/message/testcfg.py
diff --git a/test/message/testcfg.py b/test/message/testcfg.py
index bc73510c097bfc1d66c28c1cff653c86494ca781..7c53041016c8023fa1c132298a44a5303185a75a 100644
--- a/test/message/testcfg.py
+++ b/test/message/testcfg.py
@@ -59,6 +59,10 @@ class MessageTestSuite(testsuite.TestSuite):
           tests.append(test)
     return tests
 
+  def CreateVariantGenerator(self, variants):
+    return super(MessageTestSuite, self).CreateVariantGenerator(
+        variants + ["preparser"])
+
   def GetFlagsForTestCase(self, testcase, context):
     source = self.GetSourceForTest(testcase)
     result = []