If speculation is disallowed, this change lets us still do the
optimization if (a) the maps were already reliable or
(b) we are able to take stability dependencies.

Bug: v8:8820
Change-Id: I08340fc19ac87b80aa2b7ed77753dd642e89804f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1617663Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61634}