Use the general VLQ implementation for RelocInfo, rather than a custom
varint implementation. Note that this reverses the tagging logic (from
end bit to continuation bit) as this is more efficient for small values
(that now don't need to be tagged/untagged when written/read).

Change-Id: I09283f0557f9e182b4466858a2786922affb1453
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2839555
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74089}