The uninitialized case in the StoreIC doesn't use any feedback.
We could use this path to fast path some of the named stores instead of
missing to the runtime when the feedback vector is not available.

Bug: v8:8293
Change-Id: Ib3c4f843b24a377708f8db18fae10983e5633484
Reviewed-on: https://chromium-review.googlesource.com/c/1463781
Commit-Queue: Mythri Alle <mythria@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59580}