Port 34871edd

Original Commit Message:

    Partial implementation of v128.const, only the optimized case for all 0s
    and all 1s. The other cases bailout to TurboFan for now, and will be
    added in subsequent patches.

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

Change-Id: I948380f0859b49bcc5a55d239b24a93b1cd5fd04
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2292113Reviewed-by: Junliang Yan <jyan@ca.ibm.com>
Commit-Queue: Milad Farazmand <miladfar@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#68793}