Distinguish between generic Tagged and Smi in-object fields, and special
case (boxed) double values and string data rather than lumping those
into generic "raw data"

Change-Id: I5d635434ab94065c077a40110948424c31ead73d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1718154
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62914}