We can make better inlining decisions in TurboFan if the CallIC will
provide the feedback that it's seen multiple closures that share the
same SharedFunctionInfo. This is not difficult to do, and it fixes
some frustrating performance cliffs.

Thanks to Bmeurer@chromium.org for the prototype CL, rebased from his
project a year ago.

Bug: v8:2206, v8:10100
Change-Id: I4248145ea67216f9a23efa175bbe90e7a9ee0ec4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2054100
Commit-Queue: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66512}