This is a reland of ab089c78, after
making a flaky test more robust.

Original change's description:
> [turbofan] Prepare for moving part of CreateGraph into the background
>
> - 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/+/1781682
> Reviewed-by: Maya Lekova <mslekova@chromium.org>
> Commit-Queue: Georg Neis <neis@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#63515}

Bug: v8:7790
Change-Id: Ia6f4c1ebd82dea93c14437514d0e25b730523f75
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1781694Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63545}