One of the x86 ISA extensions is confusingly named SSSE3 (*Supplemental*
Streaming SIMD Extensions 3). SSSE3 supersedes SSE3, and is superseded
by SSE4.

This CL adds testing coverage for x86 CPUs that support SSE3
instructions, but do not support SSSE3 instructions. Chrome supports
these CPUs, and they are used by a non-trivial amount of Chrome's users
on Windows.

Change-Id: I7b1f1e0167708ae285a71530a01b9b474cb08352
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2757893
Auto-Submit: Victor Costan <pwnall@chromium.org>
Commit-Queue: Liviu Rau <liviurau@chromium.org>
Reviewed-by: Liviu Rau <liviurau@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73400}