Port 1e4bb087

Original Commit Message:

    x64 code path is different and we can't do this optimization.

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

Change-Id: I173d7339706a9c09d3e6519d1cee36fa15692aca
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1829171
Commit-Queue: Milad Farazmand <miladfar@ca.ibm.com>
Reviewed-by: Junliang Yan <jyan@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#64045}