This is a reland of f7f72b7b

This was reverted because of a test timing out on slow_path
variant (https://crrev.com/c/2237131 for details). Turns out
the test is just really slow, and was skipped on this variant
in https://crrev.com/c/2237628. Relanding without changes.


Original change's description:
> [wasm-simd] Prototype f64x2 rounding instructions
>
> Implements f64x2 ceil, floor, trunc, nearestint, for interpreter and
> x64.
>
> Bug: v8:10553
> Change-Id: I12a260a3b1d728368e5525d317d30fc9581cae04
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2213082
> Commit-Queue: Zhi An Ng <zhin@chromium.org>
> Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
> Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#68241}

Tbr: tebbi@chromium.org
Bug: v8:10553
Change-Id: I4cdc23d0556f11310d32fa066f40b057fd49d2d7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2237350
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68304}