Rolling v8/third_party/icu to 8d342a405be5ae8aacb1e16f0bc31c3a4fbf26a2

Rolling v8/tools/clang to 6261565695263bd878edd055e81ecc5e989711d6

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

Review URL: https://codereview.chromium.org/1529973004

Cr-Commit-Position: refs/heads/master@{#32873}