Add fast-variants feature to test driver.

tools/testrunner/local/testsuite.py

 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 63 matching lines @@
       return testcase.path.replace("\\", "/")
     else:
       return testcase.path
 
   def ListTests(self, context):
     raise NotImplementedError
 
   def VariantFlags(self, testcase, default_flags):
     if testcase.outcomes and statusfile.OnlyStandardVariant(testcase.outcomes):
       return [[]]
+    if testcase.outcomes and statusfile.OnlyFastVariants(testcase.outcomes):
+      return filter(lambda v: v in ["default", "turbofan"], default_flags)
     return default_flags
 
   def DownloadData(self):
     pass
 
   def ReadStatusFile(self, variables):
     (self.rules, self.wildcards) = \
         statusfile.ReadStatusFile(self.status_file(), variables)
 
   def ReadTestCases(self, context):
@@ skipping 154 matching lines @@
     return tests
 
   def GetFlagsForTestCase(self, testcase, context):
     return (testcase.flags + ["--gtest_filter=" + testcase.path] +
             ["--gtest_random_seed=%s" % context.random_seed] +
             ["--gtest_print_time=0"] +
             context.mode_flags)
 
   def shell(self):
     return self.name