This stubs out CurrentTimeValue for differential fuzzing as otherwise
the non-deterministic value leaks from Intl.DateTimeFormat format and
formatToParts.

This also affects other date creations, like Date.now(), which is
already stubbed out on the JS side. We keep that code for
backwards-compatibility to keep bisection stable.

Bug: chromium:1149050
Change-Id: Ifd82844c9fb8ce7262b55da6cf9f88f544268942
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2546685Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71294}