We don't use ICs for the Array.prototype and the Object.prototype
because the runtime has to be able to intercept them properly (for the
global protectors). So we better make sure that TurboFan doesn't
outsmart the system by storing to elements of either prototype directly.

Bug: chromium:781116
Change-Id: I0f521601ef02c1b21018abd1bf1028fd8a811e84
Reviewed-on: https://chromium-review.googlesource.com/753089
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49101}