Fix fast-variants feature in test driver.

tools/run-tests.py

Index: tools/run-tests.py
diff --git a/tools/run-tests.py b/tools/run-tests.py
index dc73a4035fc364abbadb6ac23b5afeec3ee24ffd..20f36798a7ee71c4040956ed8cc9746a2afa7c7f 100755
--- a/tools/run-tests.py
+++ b/tools/run-tests.py
@@ -44,6 +44,7 @@ import time
 from testrunner.local import execution
 from testrunner.local import progress
 from testrunner.local import testsuite
+from testrunner.local.testsuite import VARIANT_FLAGS
 from testrunner.local import utils
 from testrunner.local import verbose
 from testrunner.network import network_execution
@@ -83,13 +84,6 @@ TIMEOUT_DEFAULT = 60
 TIMEOUT_SCALEFACTOR = {"debug"   : 4,
                        "release" : 1 }
 
-# Use this to run several variants of the tests.
-VARIANT_FLAGS = {
-    "default": [],
-    "stress": ["--stress-opt", "--always-opt"],
-    "turbofan": ["--turbo-asm", "--turbo-filter=*", "--always-opt"],
-    "nocrankshaft": ["--nocrankshaft"]}
-
 VARIANTS = ["default", "stress", "turbofan", "nocrankshaft"]
 
 MODE_FLAGS = {