Revert of Convert SIMD wasm ops to runtime function calls (patchset #17 id:320001 of https://codereview.chromium.org/1991143002/ )

Reason for revert:
[Sheriff] Violates msan and tsan:
https://build.chromium.org/p/client.v8/builders/V8%20Linux%20-%20arm64%20-%20sim%20-%20MSAN/builds/9663
https://build.chromium.org/p/client.v8/builders/V8%20Linux64%20TSAN/builds/10670

Original issue's description:
> Convert SIMD machine ops to runtime function calls
>  - Add Simd128 type to Wasm AST types
>  - Add a pass that converts SIMD machine ops to runtime calls
>  - Sample opcodes Int32x4Splat, Int32x4ExtractLane and test
>  - Separate out generic SIMD Machine ops as these cannot be
>  handled by runtime functions just yet.
>
> LOG=N
> BUG=v8:4124
>
> R=bradnelson@chromium.org, bbudge@chromium.org, titzer@chromium.org
>
> Committed: https://crrev.com/73df92fc2fdbbfadc17e8ab4e58ec56ae2b3d91a
> Cr-Commit-Position: refs/heads/master@{#37789}

TBR=bbudge@chromium.org,bradnelson@chromium.org,titzer@chromium.org,gdeepti@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4124

Review-Url: https://codereview.chromium.org/2154723002
Cr-Commit-Position: refs/heads/master@{#37790}