The workaround is simple: cast to unsigned before shifting.

Bug: v8:3770
Change-Id: I5f0f7af697ec5db0ab1df3d061008940c83c5c56
Reviewed-on: https://chromium-review.googlesource.com/c/1436215Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59140}