This is a reland of commit c060af4d

Use LoadFullTagged function instead to avoid test failing
with v8_enable_verify_csa=true.

Original change's description:
> Fix CSA_CHECK failure on BE
>
> The load for external reference should be a full pointer load
> instead of tagged size.
>
> Change-Id: I3460a26abea5053ba6daa5c6ed908cb93431654a
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3842348
> Reviewed-by: Camillo Bruni <cbruni@chromium.org>
> Commit-Queue: Junliang Yan <junyan@redhat.com>
> Cr-Commit-Position: refs/heads/main@{#82625}

Change-Id: I85817634ce2de099a9fbd350defb57789cce9678
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3857442
Commit-Queue: Junliang Yan <junyan@redhat.com>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Jakob Linke <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82782}