This fixes some instances of -Wundefined-inline in the C++20 build.

Bug: chromium:1284275
Change-Id: I134e866183e1e42b9726153964af9910d03cd3b8
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3791525Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Peter Kasting <pkasting@chromium.org>
Auto-Submit: Peter Kasting <pkasting@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82080}