This reverts commit fe00fbd9.

Reason for revert: Broke on noavx https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Linux64%20-%20debug/36175/overview

Original change's description:
> [wasm-simd][liftoff] Compile double precision conversions
>
> I missed actually handling these instructions in liftoff-compiler, so
> even though the assembler functions were implemented for all archs, we
> weren't running them.
>
> This properly handles the instructions and a couple of fixes:
>
> - for arm64, typos in using signed instructions for unsigned Wasm ops
> - for arm, handle the case where dst == src, which leads to us
> overwriting src and then reading junk from the overwritten portions to
> convert
>
> Bug: v8:11265
> Change-Id: I7919280bdf395137e95075deb30ed815100df222
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2728382
> Reviewed-by: Clemens Backes <clemensb@chromium.org>
> Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
> Commit-Queue: Zhi An Ng <zhin@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#73178}

Bug: v8:11265
Change-Id: I9bce3418c5321ded38e339cd96a9e7e399190c96
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2733660
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@{#73179}