Rather than starting a new, orphaned transition tree in various bailout
cases, simply drop down into dictionary mode.

Aside from potential memory benefits, this allows us to remove
CopyGeneralizeAllFields, which was the only path along which fields
could end up in a different order than their descriptors.

Change-Id: I5577e8a1ca51f0ffdadd7504e7895f367605aa27
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1662298
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62279}