port ea06b01e https://crrev.com/c/1925613

Original Commit Message:

  [wasm-simd] Implement i64x2 add sub for arm

  Also some cleanup reordering of instruction codes.

Change-Id: I151668f4125c46b35b08ddd3640341125f6fdbdf
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1928500
Auto-Submit: Zhao Jiazhong <zhaojiazhong-hf@loongson.cn>
Reviewed-by: Bill Budge <bbudge@chromium.org>
Commit-Queue: Bill Budge <bbudge@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65124}