This drops possible remaining pattern errors from the access target. This is
necessary since sub patterns with default values (assignment expression) aren't
otherwise identifiable as being property accesses.

Bug: v8:9560
Change-Id: Ie6781c0d161e00790268f7d9db81377d045f93b6
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1725624Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62982}