port eaa0e596 (r32550)

  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.

BUG=

Review URL: https://codereview.chromium.org/1504703002

Cr-Commit-Position: refs/heads/master@{#32636}