... to avoid breaking jumbo builds.

TBR=cbruni@chromium.org, rmcilroy@chromium.org

Bug: v8:6949, v8:7310, v8:7339
Change-Id: Ifa3ff13fb064fc8716f237f90c82834e41ed7440
Reviewed-on: https://chromium-review.googlesource.com/983392Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52266}