This reverts commit 9a6567b4.

Reason for revert: MSVC compile failures https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Win64%20-%20msvc/b8851762212188482624/steps?succeeded=true&debug=true

Original change's description:
> [wasm-simd] Move test helpers into wasm-simd-utils
>
> Move many test helpers into wasm-simd-utils. These helper functions can
> potentially be useful for relaxed-simd test in the future. I left behind
> simd specific test helpers, like load extend helpers, because those are
> for simd instructions.
>
> Bug: v8:11583,v8:11384
> Change-Id: Id9ed452b06eaf5c97a5dda174b53a37aede2a937
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2783295
> Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
> Commit-Queue: Zhi An Ng <zhin@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#73675}

Bug: v8:11583
Bug: v8:11384
Change-Id: I88bcefecd62c9b453d0f51ad9b9a912339b110eb
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2787239
Auto-Submit: Zhi An Ng <zhin@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/master@{#73683}