This includes generalizing the notion of hints to allow for
unallocated functions, represented by a pair of SFI and FeedbackVector.

Bug: v8:7790
Change-Id: I7887665e1981b2039ecd626b82aebd5b5b64263c
Reviewed-on: https://chromium-review.googlesource.com/c/1424946
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58978}