This enables constant field tracking unconditionally.

TBR=jgruber@chromium.org

Bug: v8:8361
Change-Id: I02f35827d860c3e0f18a3d55cb156c088d48bc94
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1585730
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61055}