The test driver fails once in a while with no output when
listing the tests on windows, causing the testing to not
even start.

This should make that less likely if there's a flaky crash
when listing the tests.

BUG=v8:5438

Review-Url: https://codereview.chromium.org/2373043002
Cr-Commit-Position: refs/heads/master@{#39779}