It deals with strict-mode but is in a branch guarded by is_sloppy.

Change-Id: I309c187a96b5fa62956eec5bb05f50c0ce4e5ad3
Reviewed-on: https://chromium-review.googlesource.com/1243105
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56207}