Previously when an unresolved private name is not found
in the current scope but found in an outer class scope,
we forget to push it to the outer class scope so the
name would never get bound.

This patch simplifies ClassScope::ResolvePrivateNamesPartially()
and removes the search in outer class scopes since they are incomplete
at this point. Instead just push any private name that can't be
resolved in the current scope to the outer class scope so that it
gets handled later when the outer class scope is complete.

Bug: chromium:952722
Change-Id: Ia0dda74cac57a0a1e25a9a09575f55633c6093b5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1567709Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Joyee Cheung <joyee@igalia.com>
Cr-Commit-Position: refs/heads/master@{#60863}