This reverts commit 133e7f83.

Reason for revert: Breaks compilation for non-pointer-compressed x64

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: I08e7ca3a79b383d19c6baf73a721364b859d6df3
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3890916
Auto-Submit: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#83150}