Native C++ arrays cannot have size 0 and thus need a dummy element
when filled with variadic template args. std::array does not have this
limitation and makes related code easier to read.

Bug: v8:9972
Change-Id: I70304b55525bd67d966fa69c663a71c202245d14
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2000751
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Michael Stanton <mvstanton@chromium.org>
Auto-Submit: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65774}