Since any deopt-count-based heuristics should be native context
dependent, it belongs in the feedback vector rather than the SFI.

Bug: v8:6402
Change-Id: I30804d58bc1dec9150558e6ee21ee5b4dbd36c8d
Reviewed-on: https://chromium-review.googlesource.com/593661
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47014}