When an entry is allocated from the freelist, is is not correct to
`DCHECK(entry.IsFreelistEntry())` before the compare-and-swap succeeds:
another thread may have allocated the same entry in the meantime,
thereby turning it into a regular entry. However, in that case the CAS
will fail and then entry allocation will be retried.

Drive-by: factor out the common logic from AllocateAndInitializeEntry
and AllocateEvacuationEntry into a new TryAllocateEntryFromFreelist.

Bug: v8:13246
Change-Id: Idf16b67a2ca5ddeef16620a4d6f4a8a6c07d917b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3865864Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Auto-Submit: Samuel Groß <saelo@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82868}