ML-TF tiering remains very similar to Ignition-TF tiering:

- When the interrupt budget is exhausted, enter the TieringManager
  which potentially decides to tier up and sets the appropriate
  TieringState on the FeedbackVector.
- The prologue on ML function entry recognizes the TieringState (and
  also available cached TF code) and starts compilation and/or jumps
  into optimized code.

TODOs:

- ML-to-TF OSR is not yet supported.
- ML code is no longer cached on the FeedbackVector.
- Tracing is rudimentary.
- The generated function-entry prologue is fairly large and must be
  either minimized or extracted into a builtin.
- Tiering involving Sparkplug is not entirely robust yet (Sparkplug
  code may be installed with unexpected timing).

Bug: v8:7700
Change-Id: I86b0692477f51b9967f318a4093bc874344120b3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3629149Reviewed-by: Victor Gomes <victorgomes@chromium.org>
Commit-Queue: Jakob Linke <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82351}