Rolling v8/tools/clang to fc7b250f6ca03bcbcd2cd1a3e4102cb639a2814a

TBR=machenbach@chromium.org,vogelheim@chromium.org,hablich@chromium.org

Review URL: https://codereview.chromium.org/1784643005

Cr-Commit-Position: refs/heads/master@{#34649}