This reverts commit c060af4d.

Reason for revert: Fails with `v8_enable_verify_csa = true`:

```
# Fatal error in ../../src/compiler/machine-graph-verifier.cc, line 821
# TypeError: node #1503:Word32Equal uses node #1501:Load[kRepWord64] which doesn't have a compressed, tagged, or int32 representation.
#     Current block: id:187 <= id:154 <= id:183 <= id:93 <= id:144
#
#     Specify option --csa-trap-on-node=RegExpExecInternal,1503 for debugging.
```

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: Iaf9d0432157cba8c585377d33083a798c62e516c
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3848171
Auto-Submit: Jakob Linke <jgruber@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@{#82649}