Change its name to InferReceiverMapsUnsafe and add a comment that
MapInference should be used instead in new code. There are two
remaining uses (outside of MapInference) and I'm not planning to
remove them.

TBR: jarin@chromium.org
Bug: v8:9197
Change-Id: I3c89f11bbf9b4eb3a1c6f1648c2046fe409fa830
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1680540
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Auto-Submit: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62477}