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/+/2783295Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73675}