Previously the LookupIterator ignores private symbols
(including private names) for the access check. This patch
removes these exceptions so that they are always checked.

Drive-by: removes the unused should_throw parameter in
Runtime::DefineObjectOwnProperty()

Bug: chromium:1321899
Change-Id: I9677b1e377f01d966daa1603eee1ed9535ffab92
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3623419Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Joyee Cheung <joyee@igalia.com>
Cr-Commit-Position: refs/heads/main@{#80700}