The implicit ToObject operation should only be done on the receiver.
The remaining prototype chain is already guaranteed to not contain
primitives (besides null).

Bug: v8:7790
Change-Id: I6706c7648e201e8f99a1f27f98989db96a359c4e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3041672Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75905}