This is merged into the proposal:
https://github.com/WebAssembly/simd/issues/419#issuecomment-765675472.

Bug: v8:11215
Change-Id: Ibe37c4f8a977ab9af1cc2dd083f1ebb88b27acfa
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2647986Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72333}