In preperation of using d8 for running tests: Don't run d8-os when running with --isolates.

When used with d8 this can potentially interfer with the writing,
reading and deletion of files is the isolates flags makes the same
test run concurrently.
Review URL: http://codereview.chromium.org/7308006

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8540 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

test/mjsunit/mjsunit.status

@@ -142,3 +142,8 @@ regress/regress-create-exception: SKIP
 regress/regress-3218915: SKIP
 regress/regress-3247124: SKIP
 
+
+[ $isolates ]
+# d8-os writes temporary files that might interfer with each other when running
+# in multible threads. Skip this if running with isolates testing.
+d8-os: SKIP

tools/test.py

@@ -1442,7 +1442,8 @@ def Main():
         'system': utils.GuessOS(),
         'arch': options.arch,
         'simulator': options.simulator,
-        'crankshaft': options.crankshaft
+        'crankshaft': options.crankshaft,
+        'isolates': options.isolates
       }
       test_list = root.ListTests([], path, context, mode, [])
       unclassified_tests += test_list