Not best to rely on /proc presence basically when
the linux compatibily layer is enabled so
going through more programmatically.

Change-Id: Ida4973f9da6dec6e9caa6e419f3612ec5ef95048
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1710664Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65442}