Some tests need to ensure all builtins are deserialized. This adds a
helper to make that easier.

Drive-by-refactoring: Centralize lazy-deserialization tracing.

TBR=rmcilroy@chromium.org

Bug: v8:6624
Change-Id: I1f7caa6c539b12aabcba5b7b28c50ad40355848b
Reviewed-on: https://chromium-review.googlesource.com/891822
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50959}