This reverts commit dd19a400.

Reason for revert: https://ci.chromium.org/p/v8/builders/ci/V8%20Linux%20-%20debug/30448?

Original change's description:
> [wasm-simd][liftoff][x64][ia32] Implement load extend
> 
> The operations are implemented:
> 
> - i16x8.load8x8_s
> - i16x8.load8x8_u
> - i32x4.load16x4_s
> - i32x4.load16x4_u
> - i64x2.load32x2_s
> - i64x2.load32x2_u
> 
> on x64 and i32. The rest of the arch currently bail out, and will be
> implemented in subsequent patches.
> 
> The liftoff-compiler.cc code looks very similar to the one for LoadMem,
> the only difference is special handling of kSplat v.s. kExtend. kExtend
> always loads 8 bytes, so the bounds check and tracing is different.
> Compared to LoadMem there is less need for pinning, since the result is
> always going to be in a SIMD/FP register, which is different from the
> index/addr register.
> 
> The enum LoadTransformationKind was moved from
> function-body-decoder-impl.h to function-body-decoder.h so that no
> unncessary header file inclusions were needed to liftoff, and also it's
> a better place for it to live.
> 
> Bug: v8:9909
> Change-Id: I926bcc01c0c3c860223e8c08f91bc4ab3b75c399
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2203730
> Commit-Queue: Zhi An Ng <zhin@chromium.org>
> Reviewed-by: Clemens Backes <clemensb@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#67914}

TBR=clemensb@chromium.org,zhin@chromium.org

Change-Id: I2af6dfe6cd163d0dbc9f3a5ad4bfc5e622e76b63
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:9909
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2207665Reviewed-by: Zhi An Ng <zhin@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67915}