{base::Vector} comparison is easier to read (IMO), and more performant,
since {memcmp} will be used internally instead of {strncmp}.

R=ahaas@chromium.org

Bug: v8:10155
Change-Id: If92361688a85e96aa661d3e05cc9966e5ea2d04a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2164796Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67605}