This reverts commit 21e47944.

Reason for revert: Broke build https://ci.chromium.org/p/v8/builders/ci/V8%20Arm%20-%20debug/16872?

Original change's description:
> [wasm-simd][arm] Prototype i64x2.bitmask
>
> Cleanup to simulator to remove repetitive logic to get instruction
> fields.
>
> Bug: v8:10997
> Change-Id: I01f0b99f85788b41e4cab505fc94362d637c396f
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2554256
> Commit-Queue: Zhi An Ng <zhin@chromium.org>
> Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
> Reviewed-by: Bill Budge <bbudge@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#71391}

TBR=bbudge@chromium.org,jkummerow@chromium.org,v8-arm-ports@googlegroups.com,zhin@chromium.org

Change-Id: I15513cc5923db7d189d08a9faf5051e57af7190b
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:10997
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2558260Reviewed-by: Zhi An Ng <zhin@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71393}