In strict mode stores to non-existent properties throw. We should not
install a handler with the property cell for such stores. These handlers
would expect that the value exists when they see a property cell. If
this property cell gets invalidated later, it appears as if it is a
valid property cell with undefined value. This leads to an incorrect
behaviour. This cl checks if we are in strict mode and uses a slow
stub in such cases.

Bug: chromium:1067757
Change-Id: I543c6a6931530bfb13cc9a33d1dabaa756489fd1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2142255
Commit-Queue: Mythri Alle <mythria@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67151}