Also move it from post-mvp to mvp, since it is now in the proposal.

Bug: v8:11002
Change-Id: I711ee7a92e6937948c93e6028ef018188ea4c976
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2676937Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72643}