It's used rather narrowly for now -- only when we run into an
interceptor during the lookup. After the call to SetProperty, we know
more. That is, the interceptor was only there because it's a new
property, and the call to SetProperty ends up creating it.

By delaying the initialization of the IC, we recognize the (now)
created property, and can provide good feedback downstream to
TurboFan.

Bug: v8:8712
Change-Id: I4e10ba220c8363b393c6de84ce35fe5ef0e9c427
Reviewed-on: https://chromium-review.googlesource.com/c/1456090
Commit-Queue: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59481}