This is a reland of cecc666f

Depends on:
https://crrev.com/c/3043611

Original change's description:
> [build] Add V8-specific dcheck_always_on
>
> This makes the V8 dcheck control independent of Chromium's and
> prepares switching Chromium's default behavior without affecting V8
> developers or builders.
>
> Preparation for: https://crrev.com/c/2893204
>
> Bug: chromium:1225701
> Change-Id: I520b96019b04196f4420716ff3500ebd6c21666f
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3038528
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Commit-Queue: Michael Achenbach <machenbach@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#75827}

Bug: chromium:1225701
Change-Id: I56568b78592addba01793d2d14f768c9ee10103d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3041670Reviewed-by: Liviu Rau <liviurau@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75839}