It is possible that we fallback to GenericLowering for minimorphic
property accesses. So handle MinimorphicPropertyAccess in
ShouldUseMegamorphicLoadBuiltin.

Bug: chromium:1223733
Change-Id: Ia1ba8c8786be91dda841d4138cffe81185c066b0
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2997104
Commit-Queue: Mythri Alle <mythria@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75505}