This reverts commit 65515ddd.

Reason for revert: https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Linux64%20UBSan/18117/overview

Original change's description:
> [wasm-simd][arm64] Fuse add and extmul
>
> We can select a better instruction for add+extmul, using one of the
> multiply-long-accumulate instruction.
>
> Define a helper struct to pattern match Add(x, OP(y, z)) and
> Add(OP(x, y) z), and ensure that the matched OP is always on the
> LHS, to simplify checking for matches.
>
> Bug: v8:11548
> Change-Id: I7ab488b262aa9f749785f973549ccd9fad72f4c8
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2826725
> Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
> Commit-Queue: Zhi An Ng <zhin@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#76708}

Bug: v8:11548
Change-Id: Ic1560616e7ee6df917fcedbb6ad139a1a9773d68
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3144377
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/main@{#76709}