This is a reland of commit 133e7f83

Reland: Rebase onto v8_multi_arch_build fix.

Original change's description:
> [maglev] Optimize monomorphic keyed loads
>
> Add a fast path for keyed loads that are:
>
>   1. Monomorphic,
>   2. Fast elements accesses,
>   3. Not out-of-bounds (deopt on OOB),
>   4. Not holey
>
> Bug: v8:7700
> Change-Id: I4d46f4d0ce7065c93a9b092833fb16a8c9e9f94e
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3882974
> Auto-Submit: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Jakob Linke <jgruber@chromium.org>
> Commit-Queue: Leszek Swirski <leszeks@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#83149}

Bug: v8:7700
Change-Id: Ib48bdc8729757527c19d0b24864f8eab0570c3f3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3890920
Commit-Queue: Jakob Linke <jgruber@chromium.org>
Reviewed-by: Jakob Linke <jgruber@chromium.org>
Auto-Submit: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/main@{#83156}