Port 34f9bcdb

Original Commit Message:

    Implements i8x16.abs, i16x8.abs, and i32x4.abs.

R=zhin@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=
LOG=N

Change-Id: Ib32356532965a2187a8e8d9ec2cff44585020f0f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2084641Reviewed-by: Junliang Yan <jyan@ca.ibm.com>
Commit-Queue: Milad Farazmand <miladfar@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#66565}