When swizzle is called with a v128.const node, we can check that the
indices are either all in bounds, or if they are out of bounds the top
bit of each byte is set. This will match exactly pshufb behavior, and so
we can omit the paddusb (and getting external reference).

Bug: v8:10992
Change-Id: I5479a9eb92ebcfc12bedff5efd3e72bb4a43ff40
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2766222Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73583}