Prototype the instruction on the interpreter, and Arm64. Details of
instruction lowerings on all relevant architectures can be found at:
https://github.com/WebAssembly/relaxed-simd/issues/52

Bug: v8:12908
Change-Id: If8ffb82c38042191c67c9b5c23a231877d4f2159
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3679848Reviewed-by: Clemens Backes <clemensb@chromium.org>
Commit-Queue: Ilya Rezvov <irezvov@chromium.org>
Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80924}