Port eaa0e596

Original commit message:
    This drops the specific slot containing the new.target value from our
    construct stub frames. This side-channel has been deprecated and will
    no longer be accessed by any consumers.

R=mstarzinger@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=

Review URL: https://codereview.chromium.org/1494593005

Cr-Commit-Position: refs/heads/master@{#32584}