Given that we already treat feedback vector as a source of truth for
language mode of other store operations and given that the StoreGlobalIC
dispatcher does not depend on the language more anymore, we can just combine
these two bytecodes.

Bug: v8:7206
Change-Id: I27f03f2102ff79ec20fa997eb18dde816f376b00
Reviewed-on: https://chromium-review.googlesource.com/823846Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50102}