Add methods NotifyBytes(), NotifyObject() and NextBytes() to
AllocationCounter. Methods are unused for now.

Move AllocationObserver::Step after AllocationCounter methods as well.
Use SetTopAndLimit as bottleneck instead of allocation_info_.Reset.

Bug: v8:10315
Change-Id: I30049cb02e873bb08ebce606a491d99130421227
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2316103
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69060}