- Pass Refs, not Handles, to graph builder, and drop bytecode array argument
  (get it from SFI instead).
- Add some fields to FeedbackVectorRef that are needed to avoid heap access
  in BytecodeGraphBuilderPhase.
- Rename FeedbackVectorRef's SerializeSlots to Serialize, since it's more
  than just the feedback slots.
- Rearrange the last steps in PipelineCompilationJob::PrepareJobImpl such
  that CreateGraph is last.

Bug: v8:7790
Change-Id: I4b17790d1d74da41ba63ee68e3a33968662fc398
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1781682Reviewed-by: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63515}