The CL https://crrev.com/c/3807594 changed the scope retrieval search
to a DFS over the scope tree. This makes it no longer necessary to
special case for the `DefaultBaseConstructor` scope so we can delete
that code.

A separate follow-up will prune the DFS slightly but not as much as
we tried to initially.

R=kimanh@chromium.org

Bug: chromium:1348186
Change-Id: Ia54bd5e301aaeb195953b1384077cd30b6b6ef59
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3825777Reviewed-by: Kim-Anh Tran <kimanh@chromium.org>
Commit-Queue: Simon Zünd <szuend@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82377}