When bytecode is flushed we also want to flush the feedback vectors to
save memory. There was a bug in this code and we flushed
ClosureFeedbackCellArray too. Flushing ClosureFeedbackCellArrays causes
the closures created by this function before and after the bytecode
flush to have different feedback cells and hence different feedback
vectors. This cl fixes it so we only flush feedback vectors on a
bytecode flush.

Also this cl pretenures ClosureFeedbackCellArrays. Only FeedbackCells
and FeedbackVectors can contain ClosureFeedbackCellArrays which are
pretenured, so it is better to pretenure ClosureFeedbackCellArrays as
well.


Bug: chromium:1031479
Change-Id: I7831441a95420b9e5711f4143461f1eb7fa1616a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1980582
Commit-Queue: Mythri Alle <mythria@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65866}