This reverts commit 5a0938e5.

Reason for revert: Broke build https://logs.chromium.org/logs/v8/buildbucket/cr-buildbucket.appspot.com/8857098178780038608/+/steps/Check/0/logs/RunWasm_I32x4WidenI8x16S_liftoff/0

Original change's description:
> [wasm-simd][x64] Prototype i32x4.widen_i8x16_{s,u}
>
> This prototypes i32x4.widen_i8x16_s and i32x4.widen_i8x16_u for x64. It
> uses some masks and pshufb for the widening.  These masks (3 for each
> instruction) are stored as external references.
>
> Bug: v8:11297
> Change-Id: I6c8f55426bbb44b16ed552f393762c34c2524b55
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2617389
> Commit-Queue: Zhi An Ng <zhin@chromium.org>
> Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Reviewed-by: Andreas Haas <ahaas@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#72301}

TBR=neis@chromium.org,gdeepti@chromium.org,neis@google.com,ahaas@chromium.org,zhin@chromium.org

Change-Id: I83aa2e86854e39ac6afd250fdc0dfac7cdd99e6d
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:11297
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2648194Reviewed-by: Zhi An Ng <zhin@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72302}