Instead of processing batches with a fixed number of functions, process
batches with approximately the same number of bytes. This prevents
disproportionately large batches to block the pipeline.

R=ahaas@chromium.org

Bug: v8:11164
Change-Id: I7fe57abac13c5fb749a002e339c5a9b2dab607be
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2567699Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Thibaud Michaud <thibaudm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71530}